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Full text of "Chemistry Teacher’s Edition"

Chemistry Teacher's Edition 

CK-12 Foundation 
January 11, 2010 



CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook 
materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web- 
based collaborative model termed the "FlexBook," CK-12 intends to pioneer the generation 
and distribution of high quality educational content that will serve both as core text as well 
as provide an adaptive environment for learning. 

Copyright ©2009 CK-12 Foundation 

This work is licensed under the Creative Commons Attribution-Share Alike 3.0 United States 
License. To view a copy of this license, visit http://creativecommons.org/licenses/ 
by-sa/3.0/us/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San 
Francisco, California, 94105, USA. 



/lexboo< 

next generation t extbao ' 



Contents 



1 TE The Science of Chemistry 13 

1.1 Unit 1 Introduction to the Study of Chemistry 13 

1.2 Chapter 1 The Science of Chemistry 14 

1.3 Lesson 1.1 The Scientific Method 17 

1.4 Lesson 1.2 Chemistry in History 20 

1.5 Lesson 1.3 Chemistry is a Science of Materials 22 

1.6 Lesson 1.4 Matter 24 

1.7 Lesson 1.5 Energy 26 

2 TE Chemistry - A Physical Science 29 

2.1 Chapter 2 Chemistry - A Physical Science 29 

2.2 Lesson 2.1 Measurements in Chemistry 33 

2.3 Lesson 2.2 Using Measurements 34 

2.4 Lesson 2.3 Using Mathematics in Chemistry 36 

2.5 Lesson 2.4 Using Algebra in Chemistry 37 

3 TE Chemistry in the Laboratory 39 

3.1 Chapter 3 Chemistry in the Laboratory 39 

3.2 Lesson 3.1 Making Observations 42 

3.3 Lesson 3.2 Making Measurements 43 

3.4 Lesson 3.3 Using Data 45 

3.5 Lesson 3.4 How Scientists Use Data 46 

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4 TE The Atomic Theory 49 

4.1 Unit 2 Atomic Structure 49 

4.2 Chapter 4 The Atomic Theory 50 

4.3 Lesson 4.1 Early Development of a Theory 53 

4.4 Lesson 4.2 Further Understanding of the Atom 55 

4.5 Lesson 4.3 Atomic Terminology 56 

5 TE The Bohr Model of the Atom 59 

5.1 Chapter 5 The Bohr Model of the Atom 59 

5.2 Lesson 5.1 The Wave Form of Light 63 

5.3 Lesson 5.2 The Dual Nature of Light 64 

5.4 Lesson 5.3 Light and the Atomic Spectra 66 

5.5 Lesson 5.4 The Bohr Model 68 

6 TE Quantum Mechanics Model of the Atom 71 

6.1 Chapter 6 Quantum Mechanical Model of the Atom 71 

6.2 Lesson 6.1 The Wave-Particle Duality 75 

6.3 Lesson 6.2 Schrodinger's Wave Functions 76 

6.4 Lesson 6.3 Heisenberg's Contribution 78 

6.5 Lesson 6.4 Quantum Numbers 80 

6.6 Lesson 6.5 Shapes of Atomic Orbitals 82 

7 TE Electron Configurations for Atoms 85 

7.1 Chapter 7 Electron Configurations of Atoms 85 

7.2 Lesson 7.1 The Electron Spin Quantum Number 88 

7.3 Lesson 7.2 Pauli Exclusion 90 

7.4 Lesson 7.3 Aufbau Principle 91 

7.5 Lesson 7.4 Writing Electron Configurations 92 

8 TE Electron Configurations and the Periodic Table 95 

8.1 Unit 3 Periodic Relationships 95 

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8.2 Chapter 8 Electron Configurations and the Periodic Table 96 

8.3 Lesson 8.1 Electron Configurations of Main Group Elements 99 

8.4 Lesson 8.2 Orbital Configurations 100 

8.5 Lesson 8.3 The Periodic Table and Electron Configurations 102 

9 TE Relationships Between the Elements 105 

9.1 Chapter 9 Relationships Between the Elements 105 

9.2 Lesson 9.1 Families on the Periodic Table 109 

9.3 Lesson 9.2 Electron Configurations 110 

9.4 Lesson 9.3 Lewis Electron Dot Diagrams 112 

9.5 Lesson 9.4 Chemical Family Members Have Similar Properties 113 

9.6 Lesson 9.5 Transition Elements 114 

9.7 Lesson 9.6 Lanthanide and Actinide Series 116 

10 TE Trends on the Periodic Table 119 

10.1 Chapter 10 Trends on the Periodic Table 119 

10.2 Lesson 10.1 Atomic Size 123 

10.3 Lesson 10.2 Ionization Energy 125 

10.4 Lesson 10.3 Electron Affinity 126 

11 TE Ions and the Compounds They Form 129 

11.1 Unit 4 Chemical Bonding and Formula Writing 129 

11.2 Chapter 11 Ions and the Compounds They Form 130 

11.3 Lesson 11.1 The Formation of Ions 134 

11.4 Lesson 11.2 Ionic Bonding 136 

11.5 Lesson 11.3 Properties of Ionic Compounds 137 

12 TE Writing and Naming Ionic Formulas 141 

12.1 Chapter 12 Writing and Naming Ionic Formulas 141 

12.2 Lesson 12.1 Predicting Formulas of Ionic Compounds 144 

12.3 Lesson 12.2 Inorganic Nomenclature 146 

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13 TE Covalent Bonding 149 

13.1 Chapter 13 Covalent Bonding 149 

13.2 Lesson 13.1 The Covalent Bond 154 

13.3 Lesson 13.2 Atoms that Form Covalent Bonds 155 

13.4 Lesson 13.3 Naming Covalent Compounds 157 

14 TE Molecular Architecture 159 

14.1 Chapter 14 Molecular Architecture 159 

14.2 Lesson 14.1 Types of Bonds that Form Between Atoms 163 

14.3 Lesson 14.2 The Covalent Molecules of Family 2A-8A 164 

14.4 Lesson 14.3 Resonance 166 

14.5 Lesson 14.4 Electronic and Molecular Geometry 168 

14.6 Lesson 14.5 Molecular Polarity 169 

15 TE The Mathematics of Compounds 173 

15.1 Chapter 15 The Mathematics of Compounds 173 

15.2 Lesson 15.1 Determining Formula and Molecular Mass 176 

15.3 Lesson 15.2 The Mole 178 

15.4 Lesson 15.3 Percent Composition 179 

15.5 Lesson 15.4 Empirical and Molecular Formulas 181 

16 TE Chemical Reactions 183 

16.1 Unit 5 Reactions and Stoichiometry 183 

16.2 Chapter 16 ~"0303Chemical Reactions 183 

16.3 Lesson 16.1 ~"0303Chemical Equations 189 

16.4 Lesson 16.2 ~"0303Balancing Equations 190 

16.5 Lesson 16.3 ~"0303Types of Reactions 192 

16.6 Chapter 16 Assessment 194 

17 TE Mathematics and Chemical Equations 195 

17.1 Mathematics and Chemical Equations 195 

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17.2 Lesson 17.1 ~"0303The Mole Concept and Equations 198 

17.3 Lesson 17.2 ~"0303Mass-Mass Calculations 200 

17.4 Lesson 17.3 Limiting Reactant 201 

17.5 Lesson 17.4~"0303 Percent Yield 203 

17.6 Lesson 17.5 """0303 Energy Calculations 204 

18 TE The Kinetic Molecular Theory 207 

18.1 Unit 6 ~ "0303 Kinetic Molecular Explanation and the States of Matter . . . 207 

18.2 Chapter 18 ~"0303The Kinetic Molecular Theory 208 

18.3 Lesson 18.1 ~"0303The Three States of Matter 217 

18.4 Lesson 18.2~"0303Gases 219 

18.5 Lesson 18.3"""0303Gases and Pressure 220 

18.6 Lesson 18.4~"0303Gas Laws 222 

18.7 Lesson 18.5~"0303Universal Gas Law 223 

18.8 Lesson 18.6 ~"0303Molar Volume 225 

18.9 Lesson 18.7~"0303Stoichiometry Involving Gases 226 

19 TE The Liquid State 229 

19.1 Chapter 19~"0303The Liquid State 229 

19.2 Lesson 19.1 ~"0303The Properties of Liquids 233 

19.3 Lesson 19.2" "0303Forces of Attraction 234 

19.4 Lesson 19.3 ""0303 apor Pressure 236 

19.5 Lesson 19.4~"0303Boiling Point 238 

19.6 Lesson 19.5~"0303Heat of Vaporization 239 

20 TE The Solid State-HSC 243 

20.1 Chapter 20~"0303The Solid State 243 

20.2 Lesson 20.1~"0303The Molecular Arrangement in Solids Controls Solid Char- 
acteristics 251 

20.3 Lesson 20.2~"0303Melting 252 

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20.4 Lesson 20.3 ~"0303Types of Forces of Attraction for Solids 254 

20.5 Lesson 20.4 ~"0303Phase Diagrams 256 

21 TE The Solution Process 259 

21.1 Unit 7 Solutions and Their Behavior 259 

21.2 Chapter 21 The Solution Process 260 

21.3 Lesson 21.1 ~"0303The Solution Process 265 

21.4 Lesson 21. 2 ~"0303Why Solutions Occur 266 

21.5 Lesson 21.3 Solution Terminology 268 

21.6 Lesson 21.4 Measuring Concentration 269 

21.7 Lesson 21.5 Solubility Graphs 271 

21.8 Lesson 21.6 Factors Affecting Solubility 272 

21.9 Lesson 21.7 Colligative Properties 273 

21.10Lesson 21.8 Colloids 275 

2 1.11 Lesson 21.9 Separating Mixtures 277 

22 TE Ions in Solution 279 

22.1 Chapter 22 Ions in Solutions 279 

22.2 Lesson 22.1 Ions in Solution 282 

22.3 Lesson 22.2 Covalent Compounds in Solution 283 

22.4 Lesson 22.3 Reactions Between Ions in Solutions 285 

23 TE Chemical Kinetics 287 

23.1 Unit 8 Chemical Kinetics and Equilibrium 287 

23.2 Chapter 23 Chemical Kinetics 288 

23.3 Lesson 23.1 Rate of Reactions 295 

23.4 Lesson 23.2 Collision Theory 296 

23.5 Lesson 23.3 Potential Energy Diagrams 297 

23.6 Lesson 23.4 Factors That Affect Reaction Rates 299 

23.7 Lesson 23.5 Reaction Mechanism 301 

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24 TE Chemical Equilibrium 303 

24.1 Chapter 24 Chemical Equilibrium 303 

24.2 Lesson 24.1 Introduction to Equilibrium 306 

24.3 Lesson 24.2 Equilibrium Constant 308 

24.4 Lesson 24.3 The Effect of Applying Stress to Reactions at Equilibrium . . . 309 

24.5 Lesson 24.4 Slightly Soluble Salts 311 

25 TE Acids and Bases 313 

25.1 Unit 9 Chemistry of Acids and Bases 313 

25.2 Chapter 25 Acids and Bases 314 

25.3 Lesson 25.1 Arrhenius Acids 319 

25.4 Lesson 25.2 Strong and Weak Acids 321 

25.5 Lesson 25.3 Arrhenius Bases 322 

25.6 Lesson 24.4 Salts 323 

25.7 Lesson 25.5 pH 324 

25.8 Lesson 25.6 Weak Acid/Base Equilibria 326 

25.9 Lesson 25.7 Bronsted Lowry Acids-Bases 327 

25. 10 Lesson 25.8 Lewis Acids and Bases 329 

26 TE Water, pH and Titration 331 

26.1 Chapter 26 Water, pH, and Titration 331 

26.2 Lesson 26.1 Water Ionizes 337 

26.3 Lesson 26.2 Indicators 339 

26.4 Lesson 26.3 Titrations 341 

26.5 Lesson 26.4 Buffers 343 

27 TE Thermodynamics - HS Chemistry 345 

27.1 Unit 10 Thermodynamics 345 

27.2 Chapter 27 Thermodynamics 345 

27.3 Lesson 27.1 Energy Change in Reactions 348 



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27.4 Lesson 27.2 Enthalpy 349 

27.5 Lesson 27.3 Spontaneous Processes 350 

27.6 Lesson 27.4 Entropy 352 

27.7 Lesson 27.5 Gibb's Free Energy 353 

28 TE Electrochemistry 355 

28.1 Unit 11 Electrochemistry 355 

28.2 Chapter 28 Electrochemistry 355 

28.3 Lesson 28.1 Origin of the Term Oxidation 360 

28.4 Lesson 28.2 Oxidation-Reduction 361 

28.5 Lesson 28.3 Balancing Redox Equations Using the Oxidation Number Method 363 

28.6 Lesson 28.4 Electrolysis 364 

28.7 Lesson 28.5 Galvanic Cells 365 

29 TE Nuclear Chemistry 369 

29.1 Unit 12 Nuclear Chemistry 369 

29.2 Chapter 29 Nuclear Chemistry 369 

29.3 Lesson 29.1 Discovery of Radioactivity 375 

29.4 Lesson 29.2 Nuclear Notation 377 

29.5 Lesson 29.3 Nuclear Force 379 

29.6 Lesson 29.4 Nuclear Disintegration 380 

29.7 Lesson 29.5 Nuclear Equations 382 

29.8 Lesson 29.6 Radiation Around Us 384 

29.9 Lesson 29.7 Applications of Nuclear Energy 386 

30 TE Organic Chemistry 389 

30.1 Chapter 30 Organic Chemistry 389 

30.2 Lesson 30.1 Carbon, A Unique Element 396 

30.3 Lesson 30.2 Hydrocarbons 397 

30.4 Lesson 30.3 Aromatics 399 

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30.5 Lesson 30.4 Functional Groups 400 

30.6 Lesson 30.5 Biochemical Molecules 402 



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Chapter 1 

TE The Science of Chemistry 



1.1 Unit 1 Introduction to the Study of Chemistry 
Outline 

This unit, Introduction to the Study of Chemistry, includes three chapters that introduce 
students to the Science of Chemistry. 



• Chapter 1 The Science of Chemistry 

• Chapter 2 Chemistry - A Physical Science 

• Chapter 3 Chemistry in the Laboratory 



Overview 

The Science of Chemistry 

This chapter details the scientific method while the core of the chapter gives a brief history 
of chemistry and introduces the concepts of matter and energy. 

Chemistry - A Physical Science 

This chapter covers measurement and the mathematics of measurement and formulas. 

Chemistry in the Laboratory 

This chapter covers qualitative versus quantitation observations and data handling tech- 
niques. 

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1.2 Chapter 1 The Science of Chemistry 
Outline 

The Science of Chemistry chapter consists of five lessons that detail the scientific method 
while the core of the chapter gives a brief history of chemistry and introduces the concepts 
of matter and energy. 

• Lesson 1.1 The Scientific Method 

• Lesson 1.2 Chemistry in History 

• Lesson 1.3 Chemistry is a Science of Materials 

• Lesson 1.4 Matter 

• Lesson 1.5 Energy 

Overview 

In these lessons, students will explore: 

• The advancements of mankind in transportation, communication, and medicine and 
the use of scientific methods. 

• The definition and history of chemistry, the law of conservation of mass, and the use 
of scientific models. 

• The role of a chemist as a scientist who studies the properties of matter. 

• The definition and composition of matter, and the difference between mass and weight. 

• The definition and forms of energy, and the law of conservation of matter and energy. 

• The concept map below provides a visual representation of how the chapter concepts 
are related. 



Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

*What is Mass-Energy Equivalence? 

Albert Einstein is best known for his theories of relativity. There are two parts to the theory. 
The first part is the special theory of relativity, which was proposed in 1905. The second 
is the general theory of relativity, which was proposed in 1915. Einstein's special theory of 
relativity describes the motion of particles moving close to the speed of light. Mass-energy 
equivalence is a consequence of the special theory of relativity. Mass-energy equivalence is 
the concept that a measured quantity of energy is equivalent to a measured quantity of mass. 



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The formula E = mc 2 expresses the connection between mass and energy. Here E represents 
energy, m represents mass, and c represents the speed of light in a vacuum. Because the 
speed of light is a very large number (299,792,458 m/s) and it is squared, the equation shows 
that very small amounts of mass can be converted into very large amounts of energy and 
vice versa. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 1. 
Class Periods per Lesson 

Table 1.1: 



Lesson 



Number of 60 Minute Class Periods 



1.1 The Scientific Method 2.0 

1.2 Chemistry in History 0.5 

1.3 Chemistry is a Science of Materials 2.0 

1.4 Matter 1.0 

1.5 Energy 1.5 



Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the Flexbook for Chapter 1. 

Chapter 1 Materials List 

Table 1.2: 



Lesson 



Strategy or Activity 



Materials Needed 



1.2 Chemistry in History Demonstration 

1.3 Chemistry is a Science of Demonstration 

Materials 

1.5 Energy Demonstration 



vinegar, baking soda, soda 
bottle, balloon 
lighter, birthday candle 

glycerin, beaker, metal 
spoon 



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Multimedia Resources 

You may find these additional web-based resources helpful when teaching The Science of 
Chemistry. 

• A list of forms of energy. http://web.singnet.com.sp/~stepchin/Forms.htm 

Possible Misconceptions 

A. 

Identify: 

Students may confuse theories and hypotheses. This misconception may arise because of 
the everyday use of the word theory as in, "it's just a theory" or " tell us your theory." 
Also, some students may relate these terms in a hierarchical manner in that they may think 
that hypotheses become theories, which in turn become scientific laws. It is important that 
student are able to correctly define the terms: " hypothesis," "theory" and "law," as well 
have a clear understanding of the relationships among them. 

Clarify: 

A hypothesis is a proposal intended to explain a set of observations. Not all hypotheses 
become theories. A theory is a hypothesis that has been supported with repeated testing. 
A law is a relationship that exists between specific observations. In other words, a law is a 
relationship that always applies under a given set of conditions. 

Promote Understanding: Have students use a dictionary to define these three terms. Explain 
to students that there is no, "hierarchy of terms." In other words, a theory is not better than 
a hypothesis, and a law is not better than a theory. Point out that hypotheses, laws and 
theories each have their place in science. On the board, draw a Venn diagram to illustrate 
the relationship between a scientific theory and a scientific law. Label the circle on the left, 
"scientific theory." Label the circle on the right, "scientific law." Have students define each 
term in the appropriate circle. In the section where the two circles overlap, have students 
come up with some similarities between a scientific theory and a scientific law. 

Discuss: 

At the end of the lesson ask, "What are some similarities between a scientific theory and a 
scientific law?" (Both are based on observation and experimentation.) 

Ask: 

What are some differences between a scientific theory and a scientific law? 

(A theory is more of an explanation whereas a law is just a statement or description of a 
relationship.) 

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Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Chapter 1 

Table 1.3: 



Lesson 



California Stan- SSES Standards 
dards 



AAAS Standards 



1.1 The Scientific lc, Id, If, lg, lj, Ik, 

Method In 

1.2 Chemistry in If, lg, Ik, In 
History 

1.3 Chemistry is a lg, 11, In 
Science of Materials 



1.3 Lesson 1.1 The Scientific Method 



Key Concepts 

In this lesson, students explore the advancements of mankind in transportation, communi- 
cation, and medicine, and gain an appreciation for scientific methods. 



Lesson Objectives 



Describe the steps involved in the scientific method. 

Appreciate the value of the scientific method. 

Recognize that in some cases not all the steps in the scientific method occur, or they 

do not occur in any specific order. 

Explain the necessity for experimental controls. 

Recognize the components in an experiment that represent experimental controls. 



17 



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Lesson Vocabulary 

hypothesis 

theory 

law 

experiment 

scientific method 

superstition 

Strategies to Engage 

• Before exploring the information in this lesson, write the following phrase on the board: 
"A method of thinking that allows us to discover how the world around us works." 
Encourage students to focus on the key word, "discover" in the phrase. Facilitate 
a discussion with students about how discovery in science differs from discovery in 
religion, and philosophy. (In religion, discovery is based on faith/divine revelation. In 
philosophy, discovery is based on logical reasoning.) Point out to students that religion, 
philosophy, and science attempt to discover how the world around us works. The means 
by which this discovery occurs varies among the three. Explain to students that in this 
lesson, they will learn how science makes use of scientific methods to discover how the 
world around us works. 

• Ask students, "Have you ever walked into a room, pulled the chain to turn on a lamp, 
and it did not turn on?" Facilitate a discussion with students about what they would 
do next. (Maybe they would guess that the light bulb needs to be replaced. If replacing 
the light bulb does not work, maybe they would try plugging the lamp into a different 
outlet or plugging another appliance into the same outlet to see if there was something 
wrong with the outlet.) Point out to students that this scenario is an example of 
scientific methods at work. Explain to students how this scenario involves the use 
of scientific methods to generate and test hypotheses. (Developed an educated guess 
about the solution to the problem- hypothesis. Used controlled tests to confirm or 
reject the hypotheses.) 

Strategies to Explore 

This lesson includes a review of the last 3,000 years in the history of human transportation, 
communication, and medicine. Before reading, prepare less proficient readers by having 
students write the following on the top of separate sheets of notebook paper: 

Transportation in 1000 B.C. 

Transportation in 1830 

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Transportation in 1995 
Communication in 1000 B.C. 
Communication in 1830 
Communication in 1995 
Medical Treatment in 1000 B.C. 
Medical Treatment in 1830 
Medical Treatment in 1995 

As they read each section have them write key points under each heading. This will give the 
students a quick reference and help them to organize the information. Instruct students to 
write a one-paragraph summary of the information they have read in each section. DI Less 
Proficient Readers 



Strategies to Extend and Evaluate 

• Ask students if they would describe the relationship between science and religion and/or 
the relationship between science and philosophy to be one of conflict, independence, 
dialogue, or integration. Have students support their opinions with examples from the 
text. 



• Freeman Dyson, a noted physicist, said that the most important invention of mankind 
was hay. Facilitate a discussion with students about why he might have made this 
statement based on the readings of the first two pages. 

• Read each statement in the lesson summary. Have students indicate whether or not 
they understand each statement by using thumb up/thumb down to show "Yes" or 
"No." Whenever a student uses a thumb down to show "No," use this as an opportunity 
to review this concept with the class. DI English Language Learners 

Review Questions 

Have students answer the Lesson 1.1 Review Questions that are listed at the end of the 
lesson in the FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Lesson Assessment: Lesson 1.1 Quiz 

Provided to teachers upon request at teachers-requests@ckl2.org. 

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1.4 Lesson 1.2 Chemistry in History 
Key Concepts 

In this lesson, students explore the definition and history of chemistry, the Law of Conser- 
vation of Mass, and the use of scientific methods. 

Lesson Objectives 

• Give a brief history of how chemistry began. 

• State the Law of Conservation of Mass. 

• Explain the concept of a model, and create simple models from observations. 

Lesson Vocabulary 

• hypothesis 

• theory 

• law 

• scientific method 

• chemistry 

Strategies to Engage 

• Before beginning the lesson, ask students to predict which of the following two state- 
ments are true and which statement is false: 

a) Chemistry began as the quest for a way to transform common metals into gold. (True) 

b) "Chemistry" was derived from an Arabic word. (True) 

c) New matter is formed in chemical reactions. (False) 

Ask students to make their predictions based on what they already know. Have a volunteer 
who answered correctly that the first two statements are true and the last statement false 
explain how they came up with their answer. 

Strategies to Explore 

• As you explore the section entitled, "The Origins of Chemistry Was Multicultural," 
have students write down what they believe to be the main idea of each paragraph. 
Instruct each student to pair up with another student and come to a consensus as to 

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what they believe to be the main idea. Have each pair of students team with another 
pair, so that they are in groups of four and again, come to a consensus. Have each 
group of students share results with the class. DI Less Proficient Readers 

• As you explore the section entitled, "The Origins of Chemistry Was Multicultural," 
students will come across the term "quantitative." Students often have trouble telling 
the difference between quantitative (numerical) data and qualitative (descriptive) data. 
Have students observe Figure 1.16. Instruct students to come up with three examples 
of qualitative data about the man in the picture. He is tall, wearing blue pants, and 
smells good, etc. Instruct student to come up with three examples of quantitative data 
about the man in the picture. He weighs 180 lbs., is 5'7" tall, and his body temperature 
is 98.6°C. 

• Demonstrate the law of conservation of mass by pouring 15 mL of vinegar into an 
empty bottle. Pour about 5 grams of baking soda into a balloon. Place the balloon 
onto the top of the bottle being careful not to allow any of the baking soda to fall inside 
of the bottle. Obtain the mass of the soda bottle and balloon. Allow the baking soda 
to fall into the vinegar. After the reaction has occurred, obtain the mass of the soda 
bottle and balloon. Explain to the students that, according to the law of conservation 
of mass, in an ordinary chemical reaction, matter is not created nor destroyed, but 
may change form. 

Strategies to Extend and Evaluate 

• Robert Boyle is often called the father of modern chemistry. This honor is also some- 
times given to Antoine Lavoisier. Choose a few students and have them debate which 
chemist should be regarded as the father of modern chemistry. Students should be 
prepared to defend their choices and try to convince the remaining students that the 
chemist is the father of modern chemistry. At the end of the debate, have the students 
vote on which group defended their chemist better. 

• Read each statement in the lesson summary. Have students indicate whether or not 
they understand each statement by using thumb up/thumb down to show "Yes" or 
"No." Whenever a student uses a thumb down to show "No," use this as an opportunity 
to review this concept with the class. DI English Language Learners 



Review Questions 

Have students answer the Lesson 1.2 Review Questions that are listed at the end of the 
lesson in the FlexBook. 



21 www.ckl2.org 



Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



Lesson Assessment: Lesson 1.2 Quiz 

Provided to teachers upon request at teachers-requests@ckl2.org. 

1.5 Lesson 1.3 Chemistry is a Science of Materials 
Key Concepts 

In this lesson, students explore the role of a chemist as a scientist who studies the properties 
of matter. 



Lesson Objectives 

• Give examples of chemical properties a scientist might measure or observe in a labo- 
ratory. 

• Explain the difference between a physical change and a chemical change, giving exam- 
ples of each. 

• Identify the situations in which mass can be converted to energy and energy can be 
converted to mass. 



Lesson Vocabulary 

• alloy 

• physical change 

• chemical change 



Strategies to Engage 

• Have students observe Figure 3. Facilitate a discussion with students about how ev- 
eryday life would be different without plastics. Explain to students that plastics are 
just one of many products that came about through scientists' attempts to control the 
properties of matter in order to use them to our advantage. 

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Strategies to Explore 

• Have students read the lesson objectives. Instruct students to create a five-question 
quiz from those three objectives. Have each student exchange quizzes with a classmate. 
As students explore this lesson, instruct them to answer the five questions. At the end 
of the lesson, have them give the quiz back to the original student who will grade the 
quiz. Encourage students to discuss discrepancies. 

• Demonstrate the difference between chemical and physical changes using a birthday 
candle. Use a Bunsen burner, lighter, or match to melt one end of a candle. Allow 
students to observe the melting candle and the melted candle wax that results. Then, 
light the candlewick and allow it to burn. Facilitate a discussion with students about 
the difference between melting and burning the candle. Students should notice that, 
in the case of melting, the wax was the same substance as the candle. If students 
mention that when the candle was burned it "disappeared", inform them that it did 
not "disappear". Rather it was changed into carbon dioxide gas and water vapor. 
Emphasize to students that when a substance undergoes a physical change, as was 
the case when the candle melted, no new substances are produced. On the other 
hand, when a substance undergoes a chemical change, as was the case when the candle 
burned, new substances are formed. 

Strategies to Extend and Evaluate 

• Have interested students participate in a mock trial in which plastics are the defendants. 
Have a team of student-lawyers defend plastics and another group of student-lawyers 
prosecute plastics. The remainder of the class will serve as the jury. Encourage students 
to focus their arguments on the benefits and consequences of plastics on society and 
the environment. 



Challenge interested students to choose a material such as paper, sugar, or water. 
Instruct them to write up methods to demonstrate the material undergoing either a 
physical change or a chemical change, and if possible, perform their demonstration for 
the class. Have the class determine whether each change is physical or chemical. 



Review Questions 

Have students answer the Lesson 1.3 Review Questions that are listed at the end of the 
lesson in the FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



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Lesson Assessment: Lesson 1.3 Quiz 

Provided to teachers upon request at teachers-requests@ckl2.org. 

1.6 Lesson 1.4 Matter 
Key Concepts 

In this lesson, students explore the definition and composition of matter. Students will also 
explore the difference between mass and weight. 

Lesson Objectives 

• Define matter and explain how it is composed of building blocks known as "atoms." 

• Distinguish between mass and weight. 

Lesson Vocabulary 

matter 

atom 

element 

molecule 

Periodic Table 

mass 

weight 

volume 



Strategies to Engage 

• Introduce lesson concepts by asking students to observe Figure 1.25 and recall what 
they know about matter. Guide them in focusing their prior knowledge. 

Ask: What are some things that all objects have in common? (All objects are composed of 
matter.) 

Ask: How do you know that an ant is composed of matter? (It has mass and takes up 
space.) 

Ask: Name some examples of "things" that are not composed of matter. (Emotions, senses, 
ideas.) 



www.ckl2.org 24 



Ask: How do you know that these things are not composed of matter? (They do not have 
mass and do not take up space.) 



Strategies to Explore 

• Facilitate a discussion with students about the relationship between building materials 
and atoms. Ask: If building materials are like atoms, what are elements? (The elements 
would be the types of building materials such as the bricks, wood, and the insulation.) 



Write the following chemical formulas on the board: CO, CO2, C2H4, CaCOs, and 
CN. Ask: What do these chemical formulas have in common? (They all contain the 
element carbon. Point out to students that the one element, carbon, is present in all 
five of these chemical formulas. Explain to students that all compounds are made from 
elements and that elements such as carbon can combine with other elements to form 
compounds.) 

Explain to students that the relationship between mass and weight is given by the 
equation W = mg. Where "W" represents weight in Newtons, "m" represents mass in 
kilograms, and "g" represents acceleration due to gravity. Have students find out their 
weight on other planets at http://www.exploratorium.edu/ronh/weight/ 



Strategies to Extend and Evaluate 

• Have each student record the four sentences in this section that most clearly represent 
the main ideas. Read key sentences in the text and have students raise their hands 
if they have recorded that sentence. Facilitate a discussion in which students defend 
their selections. DI Less Proficient Readers 



Ask students to search for examples of the terms "mass" and "weight" being used 
incorrectly. Have them quote the claim, reference the source, and then explain what 
is wrong. 



Review Questions 

Have students answer the Lesson 1.4 Review Questions that are listed at the end of the 
lesson in the FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

25 www.cki2.0rg 



Lesson Assessment: Lesson 1.4 Quiz 

Provided to teachers upon request at teachers-requests@ckl2.org. 

1.7 Lesson 1.5 Energy 
Key Concepts 

In this lesson, students explore the definition and some forms of energy. Students will also 
explore the Law of Conservation of Matter and Energy. 

Lesson Objectives 

• Define heat and work. 

• Distinguish between kinetic energy and potential energy. 

• State the Law of Conservation of Matter and Energy. 

Lesson Vocabulary 

heat 

force 

work 

kinetic energy 

potential energy 

chemical potential energy 

Law of Conservation of Energy 

Law of Conservation of Matter and Energy 

Strategies to Engage 

• Have students read the lesson objectives. Ask students to write down and try to 
complete each objective. Instruct students to use a scale of 1-5 (1= not sure, 5 = very 
sure) to record how sure they are that they have correctly completed each objective. 
As you explore this lesson, encourage students to change their answers as necessary. 

Strategies to Explore 

• Place 100 mL of glycerin into a beaker. Have one student- volunteer obtain the temper- 
ature of the glycerin in the beaker. Have another student- volunteer use a metal spoon 

www.ckl2.org 26 



to stir the glycerin in the beaker for about 40 seconds. Have a third student- volunteer 
use a thermometer to obtain the temperature of the glycerin after it has been stirred. 
Explain to students that this demonstration shows that energy can be transferred as 
heat or work. Work is a force applied over a distance. When the student stirred the 
glycerin, work was done on the glycerin. Thermal energy was transferred from the 
particles of the glycerin to the thermometer in the form of heat. Heat is simply energy 
that is transferred from an object with a higher temperature to an object with a lower 
temperature. 

Strategies to Extend and Evaluate 

• Have students write a one-paragraph summary of this lesson. Instruct students to 
correctly use the following terms in their paragraph: energy, kinetic, potential, transfer, 
heat, work, and temperature. 

Review Questions 

Have students answer the Lesson 1.5 Review Questions that are listed at the end of the 
lesson in the FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Lesson Assessment: Lesson 1.5 Quiz 

Provided to teachers upon request at teachers-requests@ckl2.org. 



27 www.ckl2.org 



www.ckl2.org 28 



Chapter 2 

TE Chemistry - A Physical Science 



2.1 Chapter 2 Chemistry — A Physical Science 
Outline 

The chapter Chemistry - A Physical Science consists of four lessons that cover measurement 
and the mathematics of measurement and formulas. 

• Lesson 2.1 Measurements in Chemistry 

• Lesson 2.2 Using Measurements 

• Lesson 2.3 Using Mathematics in Chemistry 

• Lesson 2.4 Using Algebra in Chemistry 

Overview 

In these lessons, students will explore: 

• The units used to express mass, volume, length, and temperature. 

• Metric prefixes, scientific notation, and significant figures. 

• The use of dimensional analysis and significant figures in chemistry problem solving. 

• The use of algebra in chemistry problem solving. 

Science Background Information 

• The Metric System 

29 www.ckl2.org 



In the late 18th century, Louis XVI of France charged a group of scientists to reform the 
French system of weights and measures. It was widely recognized at the time that it was an 
inconsistent and disorganized collection of measurements that varied with location and often 
on obscure bases. Providing a scientifically observable system with decimally based divisions 
was the charge assigned to a group from the French Academy of Sciences, which included 
Pierre Simon LaPlace and J.J. Lagrange. They sought to create bases of measurement linked 
to the scientifically verifiable values such as the Earth's circumference. 

The unit of length, defined as a meter, was introduced in 1791 after careful measurement 
of the Earth's radius and the recognition that the planet was not perfectly spherical but 
instead possessed an oblate spheroid shape. The meter was designated as one ten-millionth 
of the length of the Earth's meridian through the city of Paris from the North Pole to the 
Equator. 

For the measurement of volume, the SI unit devised in 1795 was the cubic meter, which was 
based on the volume of a cube with sides of one meter each. The large size of this unit has 
largely resulted in the more common use of the smaller metric unit of the liter, defined as 
0.001 cubic meters. 

The kilogram was settled upon in 1799 as the mass standard, based on the value of a platinum 
bar. Now the contemporary standard for the kilogram is stored at the Bureau International 
des Poids et Mesures (BIPM) in Sevres, France as a Platinum-iridium alloy. 

The original definition of the principal time unit, the second was considered to be l/86,400th 
of the mean solar day. Due to inconsistencies in the rate of the Earth's rotation, the modern 
definition is linked to the radiation correlating to the orbital transitions of the cesium -133 
isotope. 

Since the 1960s, the International System of Units has been internationally agreed upon as 
the standard metric system. 

• What is the Kelvin Temperature Scale? 

There are three different temperature scales in use in the world today. Mainly the United 
States utilizes the Fahrenheit scale, which was introduced by Daniel Gabriel Fahrenheit 
in 1724. The non-intuitive reference points on the Fahrenheit system (212° F, 32° F for 
the boiling and freezing points of water, respectively) are replaced in the more universally 
accepted Celsius, or Centigrade system, devised by Anders Celsius in 1742, by 100° and 
0°. For scientific applications, however, both scales are inconveniently constructed in that 
a substantial portion of the scale consists of negative values for temperature. For many 
physical considerations, the use of a Celsius or Fahrenheit temperature that is a negative 
number produces an impossible result, such as in the Ideal Gas Law, (pV = nRT). 

In 1848, William Thomson Kelvin, a British physicist proposed the scale that is now named 
in his honor. In the design of this system, there are no negative values for temperature with 

www.ckl2.org 30 



the lowest value on the scale known as absolute zero. Substances at this theoretical point 
would display a complete absence of kinetic energy, thus atoms at absolute zero would cease 
all motion. 

The Kelvin and Celsius scales are routinely used in chemical measurements and are con- 
veniently constructed in that temperature change between any two points are exactly the 
same. Most laboratory thermometers available today are graduated in the Celsius system 
yet transition to the accepted SI Kelvin units is straightforward; since K = -273.15°C, 
adding 273.15 degrees to the Celsius temperature will yield the correct Kelvin value. Note 
that because the Kelvin system is an absolute scale, the degree symbol (°) is omitted in 
reporting the Kelvin temperature. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 2. 
Class Periods per Lesson 

Table 2.1: 

Lesson Number of 60 Minute Class Periods 

2.1 Measurements in Chemistry 1.0 

2.2 Using Measurements 2.0 

2.3 Using Mathematics in Chemistry 1.0 

2.4 Using Algebra in Chemistry 1.0 

Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 2. 

Chapter 2 Materials List 

Table 2.2: 

Lesson Strategy or Activity Materials Needed 

Lesson 2.1 Exploration Activity index cards 

Lesson 2.2 Metric Scavanger Hunt rulers, balances, meter 

sticks, graduated cylinders 

31 www.ckl2.org 



Table 2.2: (continued) 



Lesson Strategy or Activity Materials Needed 



Lesson 2.3 

Lesson 2.4 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 2. 

• Introduction to the Metric System http : //videos . howstuf f works . com/hsw/5890-scientif ic-met 
htm 

• Metric Conversion http://www.tecc.tv/oldmhh/manthhomeworkhotline.com/old/ 
metric .html 

• Metric Equivalents http : //www . harcoutschool . com/activity/con_math/g03c25 . html 

• Comparing and Ordering Numbers in Scientific Notation http : //www . learnalberta . 
ca/content /me jhm/html/video_ inter active/exponents/exponents Interactive .html 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Chapter 2 

Table 2.3: 

AAAS Standards 



Lesson 


California Stan- SSES Standards 




dards 


Lesson 2.1 


la, 4e, 4f, 4g 


Lesson 2.2 


la 


Lesson 2.3 


la 


w^w-§<ffl2^g 


la, le 32 



2.2 Lesson 2.1 Measurements in Chemistry 
Key Concepts 

In this lesson, students explore the units used to express mass, volume, length, and temper- 
ature. 



Lesson Objectives 

State the measurement systems used in chemistry. 

State the different prefixes used in the metric system. 

Do unit conversions. 

Use scientific notation and significant figures. 

Use basic calculations and dimensional analysis. 

Use mathematical equations in chemistry. 

Lesson Vocabulary 

International System of Units, SI 
Kelvin temperature scale 

Strategies to Engage 

• Point to an item in the room and say to students "Do you think that (item) is 10?". 
If students reply "10 what?", ask them to list some measurements to which the "10 
could possibly refer. Inches, meters, kilograms, age, c , etc. Explain to students that 
measurements without numbers are meaningless. Inform students that in this lesson, 
they will explore various measurement units. 

• Inform students that On September 23, 1999 NASA lost its $125 million Mars Climate 
Orbiter. Review findings indicate that one team used English units of measurement 
while another team used metric units. Facilitate a discussion with students about the 
importance of having and using a standardized measurement system. 

Strategies to Explore 

• Hand each group of three students an index card. Inform students that the first group 
to construct a box (without a lid) that will hold exactly 1.00 mL of water will win a 

33 www.ckl2.org 



prize. A box that is 1 cm on each edge will have a volume of 1 cm 3 , which equals 1 
mL. 



Strategies to Extend and Evaluate 

• Have two groups of students debate whether or not the U.S. should convert to the 
metric system. Students on each team will try to convince a third group of students 
that the U.S. should or should not convert to the metric system. The rest of the 
students will evaluate the arguments and decide on a winning team by vote. 



Have students record what they think is the main idea of each section. Have pairs 
of students come to a consensus on each main idea. Then, have each pair combine 
with another pair and again come to a consensus. Finally, have each group share their 
results with the class. DI LPR 



Review Questions 

Have students answer the Lesson 2.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



2.3 Lesson 2.2 Using Measurements 
Key Concepts 

In this lesson, students explore metric prefixes, scientific notation, and significant figures. 



Lesson Objectives 

• Use the metric system and its units. 

• Convert between units. 

• Use scientific notation in writing measurements and in calculations. 

• Use significant figures in measurements. Unit conversions involve creating a conversion 
factor. 

www.ckl2.org 34 



Lesson Vocabulary 

scientific notation 
significant figures 

Strategies to Engage 

• Have students research odd measurement units such as the rood, fathom, or parasang. 
Facilitate a discussion with students about why the metric system is the measurement 
system used in chemistry. 

Strategies to Explore 

• Organize a metric scavenger hunt. Give each student a list of length, mass, and volume 
quantities expressed in metric units. Instruct students to look around the classroom 
and locate objects they think have those measurements. Instruct students to use rulers, 
balances, meter sticks, and graduated cylinders to measure those objects to see if their 
guesses were correct. 

• Inform students that if they have difficulty determining whether or not a "0" in a 
measurement is significant, they can convert the measurement to scientific notation. If 
the disappears, then it was not significant. 

• Teach students the factor label method for conversions using the basic steps below. 
Have students practice using this method to perform metric conversions instead of 
simply moving the decimal point from left to right. This will prepare students to 
perform the more complex conversions they will need to be able to perform later on in 
this course. 

1) Write the number and unit. 

2) Set up a conversion factor. 

a) Place the given unit in the denominator. 

b) Place desired unit in the numerator 

c) Place a 1 in front of the larger unit. 

d) Determine the number of smaller units needed to make 1 of the larger unit. 

3) Cancel units. Solve the problem. 

35 www.ckl2.org 



Strategies to Extend and Evaluate 

• Have students create a mnemonic device to help them memorize the metric prefixes. 

• Have students write a short lesson that teaches other students the rules for determining 
the number of significant figures in a measurement. Instruct students to come up with 
examples for each rule. 



Review Questions 

Have students answer the Lesson 2.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



2.4 Lesson 2.3 Using Mathematics in Chemistry 
Key Concepts 

In this lesson, students explore the use of dimensional analysis and significant figures in 
chemistry problem solving. 



Lesson Objectives 

• Use units in problem solving. 

• Do problem solving using dimensional analysis. 

• Use significant figures in calculations. 



Lesson Vocabulary 

dimensional analysis 

Strategies to Engage 

• Write, "10 weeks" on the board and use dimensional analysis and unit conversions to 
quickly convert this quantity to seconds. Inform students that, in this lesson, they will 
learn to use dimensional analysis and unit conversions to perform complex conversions 
such as this. 

www.ckl2.org 36 



Strategies to Explore 

• Choose a place in the classroom to display the following rules for rounding to the correct 
number of significant figures in calculations. "When multiplying and dividing, limit 
and round to the least number of significant figures in any of the factors. When adding 
and subtracting, limit and round your answer to the least number of decimal places 
in any of the numbers that make up your answer." Have several students volunteer to 
write examples for each of these two rules. 



Strategies to Extend and Evaluate 

• Instruct students to begin with their age in years and use dimensional analysis and 
unit conversions to convert this value to hours and minutes. Have students express 
these values in scientific notation. 



Review Questions 

Have students answer the Lesson 2.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



2.5 Lesson 2.4 Using Algebra in Chemistry 
Key Concepts 

• In this lesson, students explore the use of algebra in chemistry problem solving. 

Lesson Objectives 

• Be able to rearrange mathematical formulas for a specific variable. 

• Have an understanding of how to use units in formulas. 

• Be able to express answers in significant figures and with units. 

Lesson Vocabulary 

None 

3 7 www.ckl2.org 



Strategies to Engage 

• When studying chemistry, students often ask, "When am I ever going to need this?" 
Inform students that many employers are looking to hire people with problem-solving 
skills. Facilitate a discussion with students about how solving chemistry problems gives 
them an opportunity to practice the problem-solving skills explored in algebra. 

Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI ELL 

Strategies to Extend and Evaluate 

Review Questions 

Have students answer the Lesson 2.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 2 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 2 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 38 



Chapter 3 

TE Chemistry in the Laboratory 



3.1 Chapter 3 Chemistry in the Laboratory 
Outline 

The chapter Chemistry in the Laboratory consists of four lessons that cover qualitative versus 
quantitative observation and data handling techniques. 

• Lesson 3.1 Making Observations 

• Lesson 3.2 Making Measurements 

• Lesson 3.3 Using Data 

• Lesson 3.4 How Scientists Use Data 

Overview 

In these lessons, students will explore: 

• Qualitative and quantitative observations. 

• The use of significant figures in measurements, accuracy and precision. 

• Data patterns and graphs. 

• Explore scientific laws, hypotheses and theories, and the construction of models in 
science. 

Science Background Information 

This information is provided for teachers who are just beginning to teach in this subject 
area. 

39 www.ckl2.org 



• The Scientific Method and the Socratic Method 

The development of the scientific method was the result of centuries of cultural and societal 
evolution. Ranging from the philosophers of the Golden Age of Greece, through the appli- 
cations of the Islamic scientists and into the ultimate flowering of the Scientific Revolution. 
The main premise of the scientific method is the synthesis of a hypothesis and the collec- 
tion of evidence, and the persistent application of experimentation designed to support or 
disprove that hypothesis. 

Among the first practitioners of what developed into the scientific method was Al Hazen (965 
- 1039), an Islamic mathematician renowned for his extensive studies in the fields of optics, 
physics and psychology. In particular, Al Hazen may have been among the very first to 
collect experimental evidence and to assemble his observations. For example, he conducted 
a series of tests on observing the light of external lanterns from an inner room to lead to the 
conclusion that the light emanated from the lanterns, not from the long held idea that light 
instead was the result of particles emerging from the eyes. 

An alternative approach, called the Socratic method, consists of a method of inquiry in some 
ways following a parallel approach to the scientific method. The dialogues of Socrates, as 
collected by his student, Plato, consisted of framing a question, often about a philosophical 
dilemma, and addressing this issue with a logical answer. The strategy was pursued with 
series of questions intended to support or undermine the problem at hand. The goal of the 
Socratic method was to arrive at a conclusion via this sequence, mainly by uncovering any 
inconsistencies in their logic. This type of reasoning, utilizing only logic and the "thought 
experiment," lead to early misconceptions about the nature of physical realities. At times, 
the lack of simple experimentation produced erroneous conclusions that remained entrenched 
in many cultures for many years. The eminent philosopher Aristotle wrote about objects 
moving with "natural motion," that is, moving according to their composition and their 
speed, a result of their weight. More than a thousand years elapsed before the experiments 
conducted by Galileo rolling different objects down a ramp removed the role of weight in 
free fall acceleration. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 3. 
Class Periods per Lesson 

Table 3.1: 



Lesson 

3.1 Making Observations 

www.ckl2.org 



Number of 60 Minute Class Periods 



0.5 



40 



Table 3.1: (continued) 



Lesson Number of 60 Minute Class Periods 



3.2 Making Measurements 0.5 

3.3 Using Data 0.5 

3.4 How Scientists Use Data 1.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chapter 3. 

Chapter 3 Materials List 

Table 3.2: 

Lesson Strategy or Activity Materials Needed 

Lesson 3.1 
Lesson 3.2 
Lesson 3.3 
Lesson 3.4 

Multimedia Resources 

You may find these additional web-based resources helpful when teaching Chapter 3: 
• Graphing tutorial http : //nces . ed . gov/nceskids/createagraph/def ault . aspx 

Possible Misconceptions 

Identify: Students may think that it is possible to measure a quantity with 100% accuracy. 

Clarify: All measured values have some degree of uncertainty. Measurements are based on 
a comparison with a standard and can only be as accurate as the instrument that produced 

it. 

Promote Understanding: Have students examine Figure 5 in the student book. You may 
want to have students examine actual samples of each piece of equipment. Facilitate a 
discussion with students about the ability of each instrument to accurately measure 2.23 

41 www.ckl2.org 



mL of water. Then, discuss with students the ability of the graduated pipet to accurately 
measure 2.23 mL of water. Explain to students that a degree of uncertainty is inherent in 
every measured value and that measurement instruments are not able to measure quantities 
with absolute accuracy. 

Discuss: At the end of the lesson ask- Why is it not possible for a measured value to be 
absolutely accurate? (All measured values have some degree of uncertainty.) 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Chapter 3 

Table 3.3: 

Lesson California Stan- SSES Standards AAAS Standards 

dards 



Lesson 3.1 


la 




Lesson 3.2 


la 




Lesson 3.3 


la 




Lesson 3.4 


la, 


le 



3.2 Lesson 3.1 Making Observations 
Key Concepts 

In this lesson, students explore qualitative and quantitative observations. 



Lesson Objectives 

• Define qualitative and quantitative observations. 

• Distinguish between qualitative and quantitative observations. 

• Use quantitative observations in measurements. 

www.ckl2.org 42 



Lesson Vocabulary 

qualitative observationsquantitative observations 

Strategies to Engage 

• Show students an object such as a stapler or pencil sharpener. Ask students to describe 
the object. Facilitate a discussion with students about the types of observations that 
were made about the object. 

Strategies to Explore 

• Have students write a narrative of what they did in the morning from the time they 
woke up until the time they got to school. Facilitate a discussion about the qualitative 
and quantitative observations contained in the narratives. 

Strategies to Extend and Evaluate 

• Have each student create a list of five observations. Instruct students to exchange pa- 
pers with a classmate who will decide if each observation is qualitative or quantitative. 

Review Questions 

Have students answer the Lesson 3.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

3.3 Lesson 3.2 Making Measurements 
Key Concepts 

In this lesson students learn the use of significant figures in measurements, accuracy and 
precision. 

Lesson Objectives 

• Match equipment type, based on the units of measurements desired. 

43 www.ckl2.org 



Determine significant figures of the equipment pieces chosen. 

Define accuracy and precision. 

Distinguish between accuracy and precision. 



Lesson Vocabulary 

significant digitsaccuracyprecision 



Strategies to Engage 

• Students are likely to have heard about accuracy and precision in advertising and pop- 
ular media. Call on volunteers to share with the class anything they may know about 
accuracy and precision. Point out correct responses, and clear up any misconceptions 
they have. Tell students they will learn more about accuracy and precision in this 
lesson. 



Strategies to Explore 

Strategies to Extend and Evaluate 

• Ask students to search for examples of the incorrect use of the terms "accuracy" and 
"precision" on the Web or in books. Have them quote the claim, reference the source, 
and then explain what is wrong. 

Lesson Worksheets 

Copy and distribute the Lesson 3.2 worksheets in the Supplemental Workbook. Ask students 
to complete the worksheets alone or in pairs as a review of lesson content. 

Review Question 

Have students answer the Lesson 3.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

www.ckl2.org 44 



3.4 Lesson 3.3 Using Data 
Key Concepts 

In this lesson students explore data patterns and graphs. 

Lesson Objectives 

• Recognize patterns in data from a table of values, pictures, charts and graphs. 

• Make calculations using formulae for slope and other formulae from prior knowledge. 

• Construct graphs for straight lines. 

• Construct graphs for curves. 

• Read graphs using the slope of the line or the tangent of the line. 

Lesson Vocabulary 

chemical reactivityperiodic tablealkali metals alkaline earth metals density graphs 
dependent variable independent variable y-intercept conversion factorlinear re- 
lationship line non-Linear relationship a line of best fit slope tangent solubility 

Strategies to Engage 

• Students are likely to be very familiar with the material explored in this section. Read 
each lesson objective and each statement in the lesson summary. Have students indi- 
cate their competency by using thumbs up or thumbs down to show "Yes" or "No." 
Whenever students use a thumbs down to show "No," use this as an opportunity to 
review the concept with the class. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• As a review of the lesson vocabulary, suggest that students make flash cards, with the 
vocabulary term on one side, and a drawing of what the term means on the other side. 
DI (ELL) 

• Have students write questions derived from Bloom's Taxonomy. Instruct students to 
research Bloom's taxonomy and write and answer one question from each of the six 
levels (knowledge, comprehension, application, analysis, synthesis, and evaluation.) 

45 www.ckl2.org 



Review Questions 

Have students answer the Lesson 3.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



3.5 Lesson 3.4 How Scientists Use Data 
Key Concepts 

In this lesson students explore scientific laws, hypotheses and theories, and the construction 
of models in science. 



Lesson Objectives 

• Define the terms law, hypothesis, and theory. 

• Explain why scientists use models. 



Lesson Vocabulary 

natural laws hypothesis theory law of conservation of mass model scientific 
method 



Strategies to Engage 

• Give students examples of models in everyday life. For example, an ultrasound pic- 
ture represents an unborn baby, a map represents an actual place, an athlete's list of 
statistics represents her performance. Facilitate a discussion with students about other 
examples of models in everyday life. 



Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI (LPR) 

www.ckl2.org 46 



Strategies to Extend and Evaluate 

• Encourage interested students to research science careers that use models. Students 
should be prepared to share their findings with the class. 

Review Questions 

Have students answer the Lesson 3.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 3 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 3 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



47 www.ckl2.org 



www.ckl2.org 48 



Chapter 4 

TE The Atomic Theory 



4.1 Unit 2 Atomic Structure 
Outline 

This unit, Atomic Structure, includes four chapters that outlines the historical development 
of the atomic model and explains the structure of the atom. 

• Chapter 4 The Atomic Theory 

• Chapter 5 The Bohr Model of the Atom 

• Chapter 6 The Quantum Mechanical Model of the Atom 

• Chapter 7 Electron Configurations for Atoms 

Overview 

The Atomic Theory 

The various models of the atom are developed from Dalton through Rutherford. This chapter 
also covers basic atomic structure and sub-atomic particles. 

The Bohr Model of the Atom 

This chapter introduces electromagnetic radiation, atomic spectra, and their roles in the 
development of the Bohr model of the atom. 

Quantum Mechanics Model of the Atom 

This chapter covers the quantum mechanical model of the atom, energy waves, standing 
waves, Heisenberg's uncertainty principle, and Schrodinger's equation. Quantum numbers, 
energy levels, energy sub-levels, and orbital shapes are introduced. 

49 www.ckl2.org 



Electron Configurations for Atoms 

This chapter covers electron spin, the Aufbau principle, and several methods for indicating 
electron configuration. 



4.2 Chapter 4 The Atomic Theory 
Outline 

The chapter Atomic Theory consists of three lessons in which the various models of the 
atom are developed from Dalton through Rutherford. This chapter also covers basic atomic 
structure and sub-atomic particles. 

• Lesson 4.1 Early Development of a Theory 

• Lesson 4.2 Further Understanding of the Atom 

• Lesson 4.3 Atomic Terminology 

Overview 

In these lessons, students will explore: 

• the development of atomic theory from the early Greek philosophers to Dalton's atomic 
theory. 

• experiments leading to the discovery of subatomic particles and the development of 
atomic models. 

• the structure of the atom. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

• Who Discovered the Neutron and How? 

The construction of the modern atomic model consisting of the central nucleus and orbit- 
ing electrons was the result of years of experimentation and the dedication and insight of 
countless scientists. Yet, well into the twentieth century, the picture remained incomplete 
and inconsistencies and questions remained to be elucidated. By 1930, the fundamental 
positive and negative particles, the proton and the electrons had been identified and their 



www.ckl2.org 50 



dispositions relative to each other characterized. Ernest Rutherford, the discoverer of the 
proton, suggested the existence of what he termed a "proton-electron" pair, a heavy, yet neu- 
tral particle found in the nucleus, mainly on the basis of the differences between the atomic 
number (Z) of several atoms and their atomic mass. Further contemplation of another heavy 
fundamental particle arose to account for the unusual radiation emitted by beryllium atoms 
when bombarded by a stream of alpha particles. Irene and Frederic Joliot-Curie found this 
unusual radiation to be capable of ejecting protons, therefore had a mass comparable to that 
of protons. This was a confusing result, in that most physicists were under the assumption 
that this radiation better corresponded with the high energy but zero mass gamma radiation. 

James Chadwick, who had worked for Ernest Rutherford at Manchester University and later 
at Cambridge University, replicated the Joliot-Curie experiment but with the intention of 
searching for a new fundamental neutral particle. Chadwick found that other light atoms 
other than beryllium gave off these new particles upon bombardment. He found the mass of 
this newly proposed particle to be about 10% greater than that of the proton, by comparing 
the velocity of the protons emitted by striking a hydrogen target with the neutral rays. 
He disproved the possibility of a proton-electron dual particle by illustrating that under no 
circumstances did the neutral ray particles degrade into smaller entities. For his efforts and 
insight, James Chadwick was awarded the Nobel Prize in Physics in 1935. 

Since the discovery of the neutron, the advent of particle accelerators has produced evidence 
for hundreds of subatomic particles. Protons and neutrons are defined as baryons or heavy 
particles, whereas the list of leptons (light particles) is extensive. 

Pacing the Lesson 

Use the table below as a guide for the time required to teach the lessons of Chapter 4. 
Class Periods per Lesson 

Table 4.1: 

Lesson Number of 60 Minute Class Periods 

4.1 Early Development of a Theory 1.0 

4.2 Further Understanding of a Theory 1.0 

4.3 Atomic Terminology 1.5 



Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 4. 



51 www.ckl2.org 



Chapter 4 Materials List 

Table 4.2: 



Lesson Strategy or Activity Materials Needed 

Lesson 4.1 
Lesson 4.2 Lab Activity vinegar, shoe boxes, various 

objects, glue 
Lesson 4.3 Copies of the periodic table 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 4: 

• Jefferson Lab question archive http : //education . j lab . org/qa/history_03 . html 

• Interactive atomic theory quiz http : //www . visionlearning . com/library/quiz_taker . 
php?qid=6&#38 ; mid=50 

• Rutherford's gold foil experiment demonstration http : //micro . magnet . f su . edu/electromag/ 
j ava/rutherf ord/ 

Possible Misconceptions 

Identify: Students may think that the atom is larger than it really is. 

Clarify: An atom is the smallest component of an element having the chemical properties of 
the element. 

Promote Understanding: Inform students that a pure copper penny would contain about 2.4 
x 10 22 atoms. Have students write the number 2.4 x 10 22 in standard form in order to see 
how large the number is. Explain to students that he population of the world is about 7 
billion (7 x 10 9 ) people. So the number of copper atoms in a pure copper penny is more 
than three trillion times the population of the world. 

Discuss: At the end of the lesson ask: "About how many atoms are there across the width 
of human hair?" (About a million.) 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 



www.ckl2.org 52 



also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Chapter 4 

Table 4.3: 

Lesson California Stan- SSES Standards AAAS Standards 

dards 



Lesson 4.1 


lg, In 


wesson 4.2 


le, lh 


wesson 4.3 


la, le 



4.3 Lesson 4.1 Early Development of a Theory 
Key Concepts 

In this lesson, students will explore the development of atomic theory from the early Greek 
philosophers to Dalton's atomic theory. 



Lesson Objectives 

• State the Law of Definite Proportions. 

• State the Law of Multiple Proportions. 

• State Dalton's Atomic Theory, and explain its historical development. 



Lesson Vocabulary 

• atomos (atomon) 

• void 

• paradox 

• law of definite proportions 

• law of multiple proportions 



Strategies to Engage 

• Introduce lesson concepts by facilitating a discussion about everyday observations. 

53 www.ckl2.ore 



Ask: What is wind? (Air movements.) 

Ask: Have you ever seen wind? (No.) 

Ask: How do you know that wind exists? (We can see its effects - tree limbs move, you can 
feel a temperature difference.) 

Ask: What is an atom? (The smallest component of an element having the chemical prop- 
erties of the element.) 

Ask: Have you ever seen an atom with your own eyes? (No.) 

Ask: What are some common observations that can be explained in terms of atoms? (Water 
evaporates, water erodes rocks, scents diffuse through a room.) 

Explain to students that although they cannot see the atoms present in a material, there 
is plenty of evidence of their existence. Let them know that in this lesson, they will learn 
about the development of the idea of the atom. 



Strategies to Explore 

• Draw a line down the center of the board or chart paper. Write the law of definite 
proportions on one side, and the law of multiple proportions on the other side. Draw 
Figure 6 below the law of definite proportions. Instruct a student-volunteer to draw 
an example, similar to Figure 6, under the law of multiple proportions that illustrates 
the law. DI ELL 



Write the basic assumptions of Dalton's atomic theory on the board or chart paper. 
Refer to it often. Facilitate discussions with students about the inaccuracies in Dalton's 
atomic theory as you explore the information in this chapter. 



Strategies to Extend and Evaluate 

• Have students create a concept map relating the terms/objectives in the chapter. 



Review Questions 

Have students answer the Lesson 4.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



www.ckl2.org 54 



4.4 Lesson 4.2 Further Understanding of the Atom 
Key Concepts 

In this lesson, students explore the experiments leading to the discovery of subatomic parti- 
cles and the development of atomic models. 

Lesson Objectives 

• Explain the experiment that led to Thomson's discovery of the electron. 

• Describe Thomson's "plum pudding" model of the atom. 

• Describe Rutherford's Gold Foil experiment, and explain how this experiment proved 
that the "plum pudding" model of the atom was incorrect. 

Lesson Vocabulary 

subatomic particles 

cathode rays 

cathode 

anode 

cathode ray tube 

phosphor 

plum pudding model 

alpha 

particles 

nucleus 

Strategies to Engage 

• Obtain about ten shoeboxes with lids. Glue a small object such as a toy, candle, or 
eating utensil inside of each shoebox. Place a marble into each shoebox. Instruct 
students to allow the marble to move around in the box and use the motion of the 
marble to guess the shape of the object inside of the shoebox. Explain to students this 
is similar to how they use clues to identify the object inside of the shoebox, scientists 
used many clues to discover the structure of the atom. 

Strategies to Explore 

• Draw a large circle on the board. As you explore this lesson, invite students to come 
to the board and change this "atomic model" to match how the model of the atom has 

55 www.ckl2.org 



changed over time. DI ELL 

• As you explore Thomson's cathode ray experiment, allow a stream of water to run 
in the sink. Charge a balloon positive by rubbing it vigorously against a wool cloth. 
Bring the charged side of the balloon next to the stream of water and watch it bend. 
Advise the students that the stream of water represents the flow of electrons from the 
anode to the cathode in this gas tube. 

Strategies to Extend and Evaluate 

• Have students write a letter convincing the reader of the atom's existence and structure. 
Instruct students to include specific information about the experiments explored in this 
lesson. 



Review Questions 

Have students answer the Lesson 4.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



4.5 Lesson 4.3 Atomic Terminology 
Key Concepts 

In this lesson, students explore the structure of the atom. 

Lesson Objectives 

• Describe the properties of electrons, protons, and neutrons. 

• Define and use an atom's atomic number (Z) and mass number (A). 

• Define an isotope, and explain how isotopes affect an atom's mass, and an element's 
atomic mass. 

Lesson Vocabulary 

• electron 

• proton 

www.ckl2.org 56 



• neutron 

• the strong nuclear force 

• atomic mass units (amu) 

• elementary charge (e) 

• atomic number (Z) 

• mass number (A) 

Strategies to Engage 

• Draw the following chart on the board or a sheet of chart paper. 

Table 4.4: 



Proton 



Neutron 



Electron 



Know 
Learned 



Ask students to think about what they know about the three subatomic particles explored 
so far in this chapter. Write some of their responses in the row marked "know". As you 
explore the information in this lesson, have student- volunteers write some of the information 
they have learned in the row marked " learned". 



Strategies to Explore 

• Give each student a copy of the periodic table. Call on students to tell you the atomic 
number and/or atomic mass given the name of the element and vice versa. 



You may want to compare the method used to calculate atomic mass from relative 
abundance to the method of calculating grades. 



For example: 

Tests = (40%)(0.78) = 31.2 
Labs = (20%) (0.86) = 17.2 
Homework = (20%) (0.90) = 18.0 
Quizzes = (20%) (0.62) = 12.4 
Average = 78.8 



57 



www.ckl2.org 



In this example, the percentages are analogs to the isotopic abundance. The average grade 
for each category would be the analog for mass number. 

Strategies to Extend and Evaluate 

• As a review of the lesson vocabulary, encourage students to make flash cards, with the 
vocabulary term on one side, and a definition or an example on the other side. 

Review Questions 

Have students answer the Lesson 4.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 4 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 4 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 58 



Chapter 5 



TE The Bohr Model of the Atom 



5.1 Chapter 5 The Bohr Model of the Atom 
Outline 

The chapter The Bohr Model of the Atom consists of four lessons that introduce electromag- 
netic radiation, atomic spectra, and their roles in the development of the Bohr model of the 
atom. 

• Lesson 5.1 The Wave Form of Light 

• Lesson 5.2 The Dual Nature of Light 

• Lesson 5.3 Light and the Atomic Spectra 

• Lesson 5.4 The Bohr Model 

Overview 

In these lessons, students will explore: 

• The wave form model of light. 

• The experiments that led to the concept of wave-particle duality. 

• Continuous and discontinuous spectra. 

• The explanations provided by the Bohr atomic model as well as its limitations. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

59 www.ckl2.org 



What is the Electromagnetic Spectrum? 



The visible light or radiant energy that illuminates our portion of the universe and enriches 
our existence with the appearance of different colors and hue intensities, was the first type of 
electromagnetic radiation evident to mankind. The remaining regions of the electromagnetic 
spectrum have only recently been elucidated. These varied regions can be differentiated on 
the basis of their wavelength (in length units of meters or millimeters), or frequency (in sec" 1 
or Hertz units). 

The first region other than the section of the spectrum visible to human eyes was the infrared 
portion. William Herschel, also known as the discoverer of the first planet to be revealed in 
modern times, Uranus, was responsible for slowing rays of light with a prism, and redirecting 
the light rays into heat-absorbing bulbs. He found that the "caloric rays" were most intense 
beyond the red portion, producing the highest absorption temperatures yet the rays could 
be refracted and reflected like visible light. 

In Germany, Johann Ritter, learning about Herschel's discovery, attempted to identify the 
complementary radiation beyond the violet region of the visible spectrum by exposing silver 
chloride crystals to refracted sunlight. Ritter originally called this new discovery "chemical 
radiation" but in time, this radiation became known as ultraviolet (beyond the violet). 

James Clerk Maxwell created the Electromagnetic Theory, which served to unify the ini- 
tially disparate fields of electricity and magnetism utilizing Maxwell's Equations. His work 
suggested that light itself was one of several types of electromagnetic waves, all traveling at 
the velocity of light, c. 

The next portion of the electromagnetic spectrum to be identified was located in the low 
energy region. In 1887, German physicist Heinrich Hertz added very long wavelength radio 
waves to the spectrum, but his research did not pursue applications of this technology as he 
felt that there was no practical use for it. It was left to Nicola Tesla and Guglielmo Marconi 
to find ways to utilize "wireless telegraphy" for the public. 

The discovery of X-rays followed soon thereafter. Wilhelm Roentgen, a Bavarian physicist, 
studied the passage of cathode rays from an induction coil through a glass tube that had 
been partially evacuated. He noticed that these rays when projected upon a fluorescent 
screen caused it to glow. Roentgen also found that these rays penetrated skin and could cast 
an image of the bones within upon on photographic plate. The first X-ray image published 
was that of Frau Roentgen's hand. 

Interest in uncovering new elements and new phenomena such as X-rays was all consuming 
as the end of the nineteenth century approached. Henri Becquerel, in Paris, discovered that 
uranium salts were the source of radioactivity. Another Parisian researcher, Paul Villard, 
also studied radioactive sources and in 1900, established that certain radioactive materi- 
als emitted what become known as gamma rays, high-energy radiation with even shorter 
wavelengths than X-rays. 



www.ckl2.org 60 



By the early twentieth century, most of the regions of the electromagnetic spectrum had 
been explored and applications of the different manifestations such as radio waves and X- 
rays had been explored. One region, however remained largely unexamined until the 1940s. 
This type of electromagnetic radiation, initially known as ultrashort radio waves, consisting 
of wavelengths in the 1 meter - one millimeter range, was used to send radar signals to 
establish distance. Use of this application expanded during World War II. Engineers at the 
Raytheon corporation building the vacuum tubes for military uses noticed that the heat 
emitted by the tubes could be used to warm their hands in the winter months. The idea of 
incorporating this technology to construct microwave ovens was implemented by Raytheon 
engineers John Spencer and Marvin Bock. The ubiquitous modern cell phones also utilize 
microwave radiation to send signals, at an intensity level too low to result in thermal heating. 

New applications are continually being added to the complement of uses for the different 
ranges of wavelengths and frequencies encompassed by the electromagnetic radiation, shed- 
ding "light" on previously unexplored areas of potential technology. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 5. 
60 Minute Class Periods per Lesson 

Table 5.1: 



Lesson 



Number of Class Periods 



5.1 The Wave Form of Light 

5.2 The Dual Nature of Light 

5.3 Light and the Atomic Spectra 

5.4 The Bohn Model 



1.5 
1.0 
1.0 
1.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chapter 5. 

Chapter 5 Materials List 



61 



www.ckl2.org 



Table 5.2: 



Lesson Strategy or Activity Materials Needed 

5.1 Exploration Activity metric ruler 

5.2 Demonstration salt 

5.3 Demonstration wintergreen mints, pliers, 

clear tape 
5.3 Exploration Activity toilet paper roll, construc- 

tion paper, clear tape, CD, 
duct tape, scissors, marker 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 5: 

• http://www.learner.org/teacherslab/science/light/ Interactive lesson on light 
and color. 

• http : //www . teachersdomain . org/resource/phy03 . sci . phys . energy . nasaspectrum/ 
Electromagnetic spectrum video. 

Possible Misconceptions 

Identify: Students may think exposure to any form of electromagnetic radiation will lead 
to death. 

Clarify: Electromagnetic radiation is the transfer of energy in the form of electromagnetic 
waves. All of the parts of the electromagnetic spectrum are referred to as electromagnetic 
radiation. We are constantly bombarded by natural sources of radiation. Although the 
highest frequency electromagnetic waves can be beneficial, absorbing too much of these 
forms of radiation can be harmful to the body. 

Promote Understanding: Have students research various applications of electromagnetic 
radiation. 

Discuss: At the end of the lesson ask "Under what circumstance is electromagnetic radiation 
harmful?". (When the body absorbs too much.) 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 



www.ckl2.org 62 



also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Chapter 5 

Table 5.3: 

Lesson [California] Stan- [NSES] Standards [AAAS] Bench- 

dards marks 



Lesson 5.1 




Lesson 5.2 


lh, lj 


Lesson 5.3 




Lesson 5.4 


li, lj 



5.2 Lesson 5.1 The Wave Form of Light 
Key Concepts 

In this lesson, students explore the waveform model of light. 

Lesson Objectives 

• The student will define the terms wavelength and frequency with respect to waveform 
energy. 

• The student will state the relationship between wavelength and frequency with respect 
to electromagnetic radiation. 

• The student will state the respective relationship between wavelengths and frequencies 
of selected colors on the electromagnetic spectrum. 



Lesson Vocabulary 



crest 

trough 

amplitude of a wave 

frequency of a wave (f) 

hertz (Hz) 

wavelength ( ) 

electromagnetic spectrum 



63 www.ckl2.org 



Strategies to Engage 

• Students are likely to have heard about various forms of electromagnetic radiation in 
popular media (e.g., gamma rays, x-rays, microwaves). Call on volunteers to share with 
the class anything they already know about electromagnetic waves. Point out correct 
responses and clear up any misconceptions. Tell students they will learn more about 
electromagnetic waves in this lesson. 

Strategies to Explore 

• Have each student draw a waveform similar to Figure 1. Instruct students to label 
one wavelength, a crest, and a trough. Have students use a ruler to measure the 
wavelength to the nearest tenth of a centimeter. Divide students into groups of three 
or four. Instruct students to compare their sketches and measurements and rank their 
waveforms from highest to lowest frequency. The higher the frequency the longer the 
wavelength. DI (ELL) 

• Point out to students that for the most part the term "light" is used to describe the 
visible portion of the electromagnetic spectrum. 

Strategies to Extend and Evaluate 

• Ask students to search for examples of myths regarding electromagnetic radiation on 
the Web or in books. Have them quote the claim, reference the source, and then explain 
what is wrong. 

Review Questions 

Have students answer the Lesson 5.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



5.3 Lesson 5.2 The Dual Nature of Light 
Key Concepts 

In this lesson students explore the experiments that led to the concept of wave-particle 
duality. 



www.ckl2.org 64 



Lesson Objectives 

• Explain the double-slit experiment and the photoelectric effect. 

• Explain why light is both a particle and a wave. 

• Use and understand the formula relating a light's velocity, frequency, and wavelength, 
c = f . 

• Use and understand the formula relating a light's frequency and energy, E = hf. 



Lesson Vocabulary 



diffraction 

double-slit experiment 
black-body radiation 
photon or quanta of light 
wave-particle duality of light 
electromagnetic spectrum 



Strategies to Engage 

• Have students create a Venn diagram highlighting the dual nature of light. Instruct 
students to label the circle on the left "Wave", the circle on the right "Particle", and 
the area where the two circles overlap "Both". Inform students that as they explore 
the information in this lesson, they will be writing experimental evidence, equations, 
and explanations in the appropriate places. 



Strategies to Explore 

• Explain to students that although light travels as a wave, it is actually made up of 
tiny energy packets, or particles called photons. You can demonstrate this potentially 
confusing concept by allowing students to observe as you pour salt from one container 
to another. Point out to students that although it looks like the salt is flowing in a 
steady stream like a liquid, they know that it is actually made up of separate grains. 



Strategies to Extend and Evaluate 

• Have students come up with a new term that explains the dual nature of light. Award 
a prize to the most creative term. 



65 www.ckl2.org 



Lesson Worksheets 

Copy and distribute the four Lesson 5.2 worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 5.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



5.4 Lesson 5.3 Light and the Atomic Spectra 
Key Concepts 

In this lesson students explore continuous and discontinuous spectra. 

Lesson Objectives 

• Distinguish between continuous and discontinuous spectra. 

• Recognize that white light is actually a continuous spectrum of all possible wavelengths 
of light. 

• Recognize that all elements have unique atomic spectra. 

Lesson Vocabulary 

• continuous electromagnetic 

• spectrum 

• discontinuous electromagnetic 

• spectrum 

• pure white light 

• atomic spectrum (emission spectrum) 

Strategies to Engage 

• Obtain a wintergreen mint and a pair of pliers. Wrap the jaws of the pliers with clear 
tape. Turn out the lights and use the pliers to break the mint. Instruct students to 

www.ckl2.org 66 



note the color of the light emitted. Inform students that in this lesson, they will learn 
what causes this flash of light. Note: Be sure to practice this demonstration ahead of 
time because not all wintergreen mints emit light when broken. "When the mint is 
crushed, electrons in the wintergreen flavor molecules absorb energy, then release it in 
the form of light." 



Strategies to Explore 

• Students can make their own spectroscopes using a toilet paper roll, an old CD, and 
construction paper. Have student remove the laminated label from the CD using duct 
tape, and use a marker to trace around the tube so as to leave a circular mark on the 
surface of the CD. Have them use scissors to cut out the circular mark. Have students 
use tape to secure the CD "diffraction grating" onto the end of the toilet paper roll. 
Instruct student to cover the other end of the toilet paper roll with black construction 
paper and use tape to hold it into place. Have them cut a narrow slit 0.5 mm x 2 
cm into the construction paper. Students must make sure the slit is parallel to the 
groves in the CD diffraction grating. Have students use their spectroscopes to observe 
different light sources. Remind students to never look directly at the sun. 



Strategies to Extend and Evaluate 

• Have students research the chemistry of fireworks and how fireworks displays relate to 
atomic emission. Students should be prepared to present their findings to the class. 
DI (GT) 



Lesson Worksheets 

Copy and distribute the four Lesson 5.3 worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 5.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



67 www.ckl2.org 



5.5 Lesson 5.4 The Bohr Model 
Key Concepts 

In this lesson students explore the explanations provided by the Bohr atomic model as well 

as its limitations. 



Lesson Objectives 

• Define an energy level in terms of the Bohr model. 



-Ft x h x c 



Find the energy of a given Bohr orbit using the equation E n 
Discuss how the Bohr model can be used to explain atomic spectra. 



Lesson Vocabulary 

• Bohr energy level 

• Bohr model of the atom 

• classical physics 

• quantum mechanics 



Strategies to Engage 

• Facilitate a discussion of the changes in the model of the atom over time. Focus the 
discussion on the location of the electron in the different atomic models. Explain to 
students that in this lesson they will explore electron arrangements in atoms. 



Strategies to Explore 

• Emphasize for students that, Bohr's concept of electrons moving in fixed orbits has 
since proven to be incorrect, Bohr did discover two very important concepts that are 
known to be true: electrons occupy specific energy levels within an atom, and energy 
is quantized. 



Strategies to Extend and Evaluate 

• Outline the main concepts of the lesson as a class. Discuss the main concepts as you 
prepare the outline. 

www.ckl2.org 68 



Copy and distribute the four Lesson 5.4 worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 5.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 5 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 5 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



69 www.ckl2.org 



www.ckl2.org 70 



Chapter 6 

TE Quantum Mechanics Model of the 
Atom 



6.1 Chapter 6 Quantum Mechanical Model of the Atom 



Outline 

The chapter Quantum Mechanical Model of the Atom consists of five lessons that cover 
the quantum mechanical model of the atom, energy waves, standing waves, Heisenberg's 
uncertainty principle, and Schrodinger's equation. Quantum numbers, energy levels, energy 
sub-levels, and orbital shapes are introduced. 

• Lesson 6.1 The Wave-Particle Duality 

• Lesson 6.2 Schrodinger's Wave Functions 

• Lesson 6.3 Heisenberg's Contribution 

• Lesson 6.4 Quantum Numbers 

• Lesson 6.5 Shapes of Atomic Orbitals 

Overview 

In these lessons, students will explore: 

• The wave and particle properties of electrons. 

• Electron wave functions and electron density. 

• The Heisenberg uncertainty principle. 



71 www.ckl2.org 



• The quantum numbers n, £, and m. 

• Atomic orbitals. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

• Spin State and Nuclear Magnetic Resonance Imaging 

While the concepts in the study of quantum mechanics may seem elusive to some students, 
many may be more familiar with one application based on the spin states of the hydrogen 
atom: Magnetic Resonance Imaging. MRI technology is based on the differing spin states 
of the hydrogen atom, usually those associated with biological water and fat molecules, and 
their interaction with strong magnetic fields and radiofrequency waves. 

Atoms with an odd number of protons or neutrons in their nucleus possess an intrinsic spin 
that is quantized. There are two magnetic spin states for the hydrogen nucleus, which can be 
described as the opposite types of physical spinning: clockwise (+1/2) and counterclockwise 
spinning (-1/2). Under normal circumstances, a collection of hydrogen nuclei would display 
random alignment and both spin states would be equal in energy (degenerate). In the 
presence of an external magnetic field, however, the hydrogen nuclei can orient with or 
against the magnetic field, with more nuclei lining up with the magnetic field at a lower 
energy value. Those nuclei with spins opposing the magnetic field would then be higher in 
energy by a value of E. If that precise amount of energy is added to the system, in the form 
of radio waves applied at right angles to the magnetic field, it can cause the lower energy 
nuclei to absorb and perform a "spin flip" to the higher energy configuration. The radio 
frequency must match or be in resonance with the nucleus' natural spin. As the "flipped" 
nuclei gradually relax and realign with the magnetic field, they resume their lower energy spin 
states and release the absorbed energy. The relaxation rates are a function of the interaction 
of the nucleus and its physical environment. Incorporation of adjustable magnetic fields 
can generate a map of very slight difference in resonance frequencies, and thus produce the 
magnetic resonance image, allowing practitioners to construct images of body tissues with a 
three-dimensional quality. 

The introduction of Magnetic Resonance Imaging has provided a diagnostic revolution in the 
medical world. Unlike X-rays and CT (computer tomography) scans, no radiation is utilized 
to produce the image. The key limitations to MRI include eliminating any interference of the 
magnetic field with metals, thus MRI patients may not have pacemakers, insulin pumps or 
prosthetic implants. Enhancement of the distinction between normal and diseased tissue is 
often needed as well, and provided by the introduction of contrast agents. These are usually 
molecules containing paramagnetic ions, such as Gd 2+ , which has seven unpaired electrons. 
These agents are administered intravenously and they serve to highlight visualization of 

www.ckl2.org 72 



tissue by shortening the relaxation time of the nuclei. Other paramagnetic agents, such as 
iron oxide and manganese agents are also used for certain applications. 

MRI examinations are performed by placing the patient inside the bore of a very large mag- 
net. Other obstacles to this diagnostic tool is that some patients experience claustrophobic 
anxiety inside the magnet, while others have found the time needed and noise incurred dur- 
ing the data acquisition to be uncomfortable. Despite these hindrances, Magnetic Resonance 
Imaging has emerged to become an impressive tool for the practice of modern medicine. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Quantum Me- 
chanical Model of the Atom. 

Class Periods per Lesson 

Table 6.1: 



Lesson 



Number of 60 Minute Class Periods 



6.1 The Wave-Particle Duality 

6.2 Schroedinger's Wave Functions 

6.3 Heisenberg's Contribution 

6.4 Quantum Numbers 

6.5 Shapes of Atomic Orbitals 



1.0 
1.0 
1.0 
1.5 
1.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Quantum Mechanical Model of the Atom. 

Quantum Mechanical Model of the Atom Materials List 

Table 6.2: 



Lesson 



Strategy or Activity 



Materials Needed 



6.1 
6.2 
6.3 
6.4 
6.5 



Exploration Activity 



Marker, paper 



73 



www.ckl2.org 



Multimedia Resources 

You may find these additional internet resources helpful when teaching Quantum Mechanical 
Model of the Atom: An interactive tour of the atom http://ParticleAdventure.org/ 
Quantum mechanics video http : //www . teachersdomain . org/resource/phy03 . sci . phys . 
fund . quantum/ 

Possible Misconceptions 

Identify: Students may think that the electron cloud is "crowded" with electrons." This 
misconception may arise because probability patterns appear to show lots of electrons. 

Clarify: Electron probability patterns represent the probability of finding a single electron 
at any given time. 

Promote Understanding: Review probability with students by covering a die with masking 
tape. Write the letter "a" on one side, the letter "b" on two sides, and the letter "c" on the 
three sides that remain. Ask students "If I were to roll the die one time, on which letter is 
the die more likely to land, and why?" It is more likely to land on the letter "c" because 
there are more "c's" than any other letter. Ask students "How would the results differ if I 
wrote the letters a, b, and c each on two sides of the die?" There would be an equal chance 
of the die landing on each letter. 

Explain to students that electron probability patterns show that probability of finding an 
electron in a given location increases, then decreases as you increase the distance from the 
nucleus. Probability patterns show the probability of finding a single electron, not the 
location of a large number of electrons. 

Discuss: At the end of the lesson ask "If I were to take a snapshot of an atom with a single 
electron, how many dots would the photograph show?" It would show only one dot. 

Ask: "What do the crowded areas versus the less crowded areas of an electron probability 
pattern show?" The crowded area show high probability of finding an electron while the less 
crowded areas show a lower probability of finding an electron in those locations. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Quantum Mechanical Model of 

the Atom 

www.ckl2.org 74 



Table 6.3: 



Lesson [California] Stan- [NSES] Standards [AAAS] Bench- 

dards marks 

6.1 lg, In 

6.2 

6.3 

6.4 

6.5 



6.2 Lesson 6.1 The Wave-Particle Duality 
Key Concepts 

In this lesson students explore the wave and particle properties of electrons. 



Lesson Objectives 

• Explain the wave-particle duality of matter. 

• Define the de Broglie relationship, and give a general description of how it was derived. 

• Use the de Broglie relationship to calculate the wavelength of an object given the 
object's mass and velocity. 



Lesson Vocabulary 

wave-particle duality of matter Matter exhibits both particle-like and wave-like prop- 
erties. 



Strategies to Engage 

• Have students draw a Bohr atomic model. Review charges, masses, and locations of 
protons, neutrons, and electrons. Re-emphasize for students that Bohr discovered two 
very important concepts that are known to be true: electrons occupy specific energy 
levels within an atom, and energy is quantized. Bohr's concept of electrons moving in 
fixed orbits has proven to be incorrect. Explain to students that in this chapter they 
will be introduced to the modern atomic model called the quantum mechanical model. 

75 www.ckl2.org 



Strategies to Explore 

• Use the equation E = hf and deBroglie's equation for wavelength, A = — - — , to 
explain the relationship between the energy of a wave and the wave's frequency, and 
the relationship between the mass of an object and the object's wavelength. Also, 
as you go through each example problem, use the equations to explain the concepts 
explored in this chapter. This will reduce English Language Learner's reliance on 
language skills. DI (ELL) 



Strategies to Extend and Evaluate 

• Challenge interested students to derive deBroglie's equation for the wavelength of a 
particle from the equation E = mc 2 and E = hf. The first student to correctly show 
the derivation may then demonstrate to the class. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 6.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers available upon request. Please send an email to teachers-requests@ckl2.org. 



6.3 Lesson 6.2 Schrodinger's Wave Functions 
Key Concepts 

In this lesson students explore electron wave functions and electron density. 

Lesson Objectives 

• Distinguish between traveling and standing waves. 

• Explain why electrons form standing waves, and what this means in terms of their 
energies. 

www.ckl2.org 76 



• Define an electron wave function and electron density and relate these terms to the 
probability of finding an electron at any point in space. 

Lesson Vocabulary 

traveling waves Waves that travel, or move. 

standing waves Waves that do not travel, or move. They are formed when two travel- 
ing waves, moving in opposite directions at the same speed run into each other and 
combine. 

electron wave function A mathematical expression to describe the magnitude, or 'height' 
of an electron standing wave at every point in space. 

electron density The square of the wave function for the electron, it is related to the 
probability of finding an electron at a particular point in space. 

Strategies to Engage 

• Preview the lesson vocabulary and lesson objectives. Have students write ten state- 
ments from the objective and vocabulary. For example; Traveling waves are waves that 
do not move. At the end of the lesson have them evaluate their earlier statements and 
change their responses when necessary. 

Strategies to Explore 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space in 
between. As you explore the lesson, have students write the "answer" to each objective. 
DI (LPR) 

• Students can use a marker and a target to demonstrate the probability distribution of 
an electron in relation to the nucleus. Instruct students to place the target on the floor 
and drop the marker from a specific height directly over the target 50 times. Explain 
to students that this activity illustrates the probability pattern for a single electron 
atom as shown in Figure 7. Point out to students that the probability of finding the 
electron increases then decreases as the distance from the nucleus increases. 

Strategies to Extend and Evaluate 

• Have students evaluate the statements introduced under the engagement section (above) 
and use this information to make a concept map of the lesson content. 

77 www.ckl2.org 



Review Questions 

Have students answer the Lesson 6.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon requests. Please send an email to teachers- 
requests@ckl2.org. 



6.4 Lesson 6.3 Heisenberg's Contribution 
Key Concepts 

In this lesson students explore the Heisenberg uncertainty principle. 

Lesson Objectives 

• Define the Heisenberg Uncertainty Principle. 

• Explain what the Heisenberg Uncertainty Principle means in terms of the position and 
momentum of an electron. 

• Explain why the Heisenberg Uncertainty Principle helps to justify the fact that a 
wave function can only predict the probable location of an electron, and not its exact 
location. 



Lesson Vocabulary 

momentum (p) The quantity you get when you multiply an object's mass by it's velocity 
(which as far as you're concerned is the same as its speed). 

Heisenberg's Uncertainty Principle Specific pairs of properties, such as momentum 
and position, are impossible to measure simultaneously without introducing some un- 
certainty. 

Strategies to Engage 

• Use this model of an atom to reveal student misconceptions and answer any questions 
students may have about electrons' arrangements in atoms. The protons and neutrons 
of this atom make up its nucleus. Electrons surround the nucleus, but they do no circle 
them like planets around a star, as this model suggests. Review the contributions of 
Bohr and de Broglie to the modern (quantum mechanical) model of the atom. Explain 



www.ckl2.org 7 8 



to students that in this lesson they will learn about the important contribution of 
Werner Heisenberg, a student of Niels Bohr. 




KEY: 







Protons 


o 


Neutrons 


o 


Electrons 



(Source: http: //commons . wikimedia. org/wiki/Image : Stylised_Lithium_Atom.png, Li- 
cense: Creative Commons) 



Strategies to Explore 

• Challenge students to re-state Heisenberg's Uncertainty Principle using as few words as 
possible. Consider awarding a prize to the student with the most concise, yet accurate 
definition. For example: Measuring the position of a particle disturbs its momentum, 
and vice versa. 



79 



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Strategies to Extend and Evaluate 

• Challenge interested students to design a model that would help others understand 
Heisenberg's Uncertainty Principle. Instruct students to use common object such as 
balls and other toys, paper clips, and rulers. Encourage students to share their models 
with their classmates. DI (GT) 

Review Questions 

Have students answer the Lesson 6.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



6.5 Lesson 6.4 Quantum Numbers 
Key Concepts 

In this lesson students explore the quantum numbers n, £, and m. 

Lesson Objectives 

• Explain the meaning of the principal quantum number, n. 

• Explain the meaning of the azimuthal quantum number, £. 

• Explain the meaning of the magnetic quantum number, m. 

Lesson Vocabulary 

quantum numbers Integer numbers assigned to certain quantities in the electron wave 

function. Because electron standing waves must be continuous and must not 'double over' 
on themselves, quantum numbers are restricted to integer values. 

principal quantum number (n) Defines the energy level of the wave function for an 
electron, the size of the electron's standing wave, and the number of nodes in that 
wave. 

node A place where the electron wave has zero height. In other words, it is a place where 
there is no electron density. 

www.ckl2.org 80 



azimuthal quantum number (£) Defines the electron sublevel, and determines the shape 
of the electron wave. 



magnetic quantum number (mi) Determines the orientation of the electron standing 
wave in space. 



Strategies to Engage 

• Point out to students that the probability distribution for an electron in a hydrogen 
atom has been explored so far. Explain to students that in this lesson they will explore 
quantum numbers, which are important when it comes to determining the shape of a 
probability pattern. 



Strategies to Explore 

• Have students create a chart of the three quantum numbers. As each quantum number 
is explored and explained, have student fill in the chart with the following informa- 
tion: name, symbol, definition, allowed values, and other important information. Have 
students save their chart for reviewing lesson content. 



Strategies to Extend and Evaluate 

• Have students use the information in the chart introduced in the exploration section 
(above) to create a five-paragraph essay explaining the quantum numbers. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 6.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teacher-requests@ckl2.org. 

81 www.ckl2.org 



6.6 Lesson 6.5 Shapes of Atomic Orbitals 
Key Concepts 

In this lesson students explore atomic orbitals. 

Lesson Objectives 

• Define an electron orbital. 

• Be able to recognize s orbitals by their shape. 

• Be able to recognize p orbitals by their shape. 

Lesson Vocabulary 

orbital A wave function for an electron defined by all three quantum numbers, n, £, and 
rrii. Orbitals define regions in space where there is a high probability of finding the 
electron. 

Strategies to Engage 

• Use this opportunity to review the contributions of Bohr, de Broglie, Schrodinger, 
Born, and Heisenberg to the modern (quantum mechanical) atomic model. Explain to 
students that in this lesson they will explore atomic orbitals, or the regions in space 
where there is a high probability of finding the electron. 

Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side, and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI (LPR) 

Strategies to Extend and Evaluate 

• Have students create a museum exhibit of the atomic models, principal scientists, 
experiments, equations, and concepts explored in this chapter. 

• Have each student create a poster illustrating the refining of the atomic theory from 
Democritus to modern atomic theory. 

www.ckl2.org 82 



Have students create a side-by-side comparison of the Bohr model and the quantum 
mechanical model of the atom. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 6.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 6 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 6 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



83 www.ckl2.org 



www.ckl2.org 84 



Chapter 7 

TE Electron Configurations for Atoms 



7.1 Chapter 7 Electron Configurations of Atoms 
Outline 

This chapter Electron Configuration of Atoms, consists of four lessons that cover electron 
spin, the Aufbau principle, and several methods for indicating electron configuration. 

• Lesson 7.1 The Electron Spin Quantum Number 

• Lesson 7.2 Pauli Exclusion Principle 

• Lesson 7.3 Aufbau Principle 

• Lesson 7.4 Writing Electron Configuration 

Overview 

In these lessons, students will explore: 

• The electron spin number, its effect on the number of electrons in an orbital and on 
the magnetic properties of an atom. 

• The Aufbau principle, and will use it to predict the orbital in which an electron will 
be found. 

• Orbital representations and electron configurations. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

85 www.ckl2.org 



Orbital Filling Order Exceptions 



In assembling the electron configurations for many-electron atoms, one tool that students 
find valuable is the diagonal rule. This rule provides a guideline that is readily remembered 
and easily followed to produce accurate electron configurations for even complicated d- and 
f- block atoms. One confusing consequence of the diagonal rule is the order of filling the 4s 
and 3d subshells. 

When these orbitals are filled, they are very close in energy. Though as the electrons begin 
to occupy the empty orbitals, the 4s level is slightly lower in energy than the 3d, thus it 
is filled first. On the other hand, when both are occupied with electrons, the 4d orbital 
becomes higher in energy. Thus, in the case that both of these filled levels are composed of 
valence electrons, the 4s level loses its valence electrons before the 3d level. 

The preferential filling of the 4s orbital can also be explained by means of the electron 
penetration effect. Due to the spherical shape of the s orbital probability density distribution, 
the likelihood that an electron is found closer to the nucleus is greater than the multi-lobed 
3d orbitals. 

The similarity in the energy levels of the 4s and 3d orbitals also leads to another interesting 
consequence. In the electron configuration of the neutral Chromium atom with 24 electrons, 
the diagonal rule suggests an electron configuration of ls 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 4 . The actual 
electron configuration is ls 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 5 , where due to the similarity in energy between 
the 4s and 3d orbitals, one electron transfers from the 4s to the 3d orbital. The net effect 
of this exchange yields half-filled 4s and 3d orbitals, and therefore can be justified in terms 
of generating additional stability. This is also the case for neutral copper atoms, with 29 
electrons and a putative electron configuration of ls 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 9 . Again as in the 
example of chromium, an electron transfer occurs, shifting one electron from the 4s orbital 
to the 3d orbital. For copper, the 4s orbital is now half-filled but added stability is attained 
by completing the 3d subshell. 

The stability afforded to half-filled orbitals is also noted among the f-block elements. For ex- 
ample, the electron configuration for Europium (atomic number 63) is ls 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 f 
whereas the next atom, Gadolinium, with atomic number 64, has the additional electron 
added to the 5d orbital in order to maintain the half-filled stability of the 4f 7 configuration. 
The electron configuration for Gadolinium is therefore ls 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 7 5d 1 . 

The unusual stability of half-filled orbitals can be explained in terms of the disruption af- 
forded by the addition of another electron to this configuration. After the orbital is half-filled, 
the next additional electron must pair up with another electron, increasing the spin-spin in- 
teraction energy and destabilizing the configuration. 

www.ckl2.org 86 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Electron Config- 
uration of Atoms. 

Class Periods per Lesson 

Table 7.1: 

Lesson Number of 60 Minute Class Periods 

7.1 The Electron Spin Quantum Number 0.5 

7.2 Pauli Exclusion Principle 1.0 

7.3 Aufbau Principle 1.0 

7.4 Writing Electron Configurations 2.0 

Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Electron Configuration of Atoms. 

Electron Configuration of Atoms Materials List 

Table 7.2: 

Lesson Strategy or Activity Materials Needed 

7.1 
7.2 
7.3 

7.4 



Multimedia Resources 

You may find these additional internet resources helpful when teaching Electron Configura- 
tion of Atoms: Lesson on atomic structure http : //www . chemtutor . com/struct . htm Apart- 
ment analogy of electron configuration http : //kaf f ee . netf irms . com/Science/activities/ 
Chem/Activity . Electron . Configuration . html 

8 7 www.ckl2.org 



Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Electron Configuration of Atoms 

Table 7.3: 

Lesson [California] Stan- [NSES] Standards [AAAS] Bench- 

dards marks 

Ti ij 

7.2 
7.3 

7.4 lg 

7.2 Lesson 7.1 The Electron Spin Quantum Number 
Key Concepts 

In this lesson students explore the electron spin number, its effect on the number of electrons 
in an orbital and on the magnetic properties of an atom. 

Lesson Objectives 

• Explain what is meant by the spin quantum number, m s . 

• Explain how the spin quantum number affects the number of electrons in an orbital. 

• Explain the difference between diamagnetic atoms and paramagnetic atoms. 

Lesson Vocabulary 

• spin quantum number, m s 

• spin-up 

• spin down 

www.ckl2.org 88 



diamagnetic electrons 
diamagnetic atom 
paramagnetic electron 
paramagnetic atom 



Strategies to Engage 



Take the time to review quantum numbers and how they describe the probable location 
of the electron, the shape of atomic orbitals, and the orientation of the orbital. Inform 
students that in this lesson they will explore a fourth quantum number, the spin 
quantum number, which describes the spin of the electron. 



Strategies to Explore 

• Have students calculate all possible quantum states for elements 1-10. 



Strategies to Extend and Evaluate 

• Challenge interested students to come up with a way to explain, model, or illustrate 
the four quantum numbers. Examples include an analogy to a home address, a colored 
chart, or balloons. Have students present their information to the class. Facilitate a 
discussion with students about the limits to the analogies and models. 



Lesson Worksheets 

Copy and distribute the Lesson 7.1 worksheet in the Supplemental Workbook named Quan- 
tum Numbers. Ask students to complete the worksheets alone or in pairs as a review of 
lesson content. 



Review Questions 

Have students answer the Lesson 7.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



89 www.ckl2.org 



7.3 Lesson 7.2 Pauli Exclusion 
Key Concepts 

In this lesson students explore the Pauli exclusion principle and its implication for electron 
arrangements in atoms. 



Lesson Objectives 

• Explain the meaning of the Pauli Exclusion Principle. 

• Determine whether or not two electrons can coexist in the same atom based on their 
quantum numbers. 

• State the maximum number of electrons that can be found in any orbital. 



Lesson Vocabulary 

• Pauli Exclusion Principle 

Strategies to Engage 
Strategies to Explore 

• Wolfgang Pauli was a close friend of both Werner Heisenberg and Niels Bohr. Facilitate 
a discussion with students about some of the conversations these three friends might 
have had. 

Strategies to Extend and Evaluate 

Write each of the following statements on the board or on chart paper: 



• No two electrons in an atom can have the same four quantum numbers. 

• No atomic orbital can contain more than two electrons. 

• Electrons in the same atom with the same spin must be in different orbitals. 

• Electrons in the same orbital of the same atom must have different spins. 

• Have students come up with example problems that illustrate each statement. 

www.ckl2.org 90 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 7.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



7.4 Lesson 7.3 Aufbau Principle 
Key Concepts 

In this lesson students explore the Aufbau Principle and will use it to predict the orbital in 
which an electron will be found. 



Lesson Objectives 

• Explain the Aufbau Principle. 

• Given two different orbitals, predict which the electron will choose to go into. 



Lesson Vocabulary 

• Aufbau Principle 

Strategies to Engage 
Strategies to Explore 

• Have students come up with more descriptive names for both the Pauli exclusion 
principle, and the Aufbau Principle. 

91 www.ckl2.org 



Strategies to Extend and Evaluate 

• Challenge interested students to come up with a skit illustrating the Aufbau Principle. 
Have them perform the skit for their classmates. Then facilitate a class discussion of 
the limitations of the skit to accurately represent the Aufbau Principle. 



Use student descriptions to come up with a composite diagram of the arrangement of 
electrons in energy levels, sublevels, and orbitals. This will give you the opportunity 
to review lesson concepts and clear up any misconceptions students may have about 
the lesson content. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 7.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



7.5 Lesson 7.4 Writing Electron Configurations 
Key Concepts 

In this lesson students will explore orbital representations and electron configurations. 



Lesson Objectives 

• Figure out how many electrons can exist at any given sublevel. 

• Figure out how many different sublevels can exist at any given energy level. 

• Be able to write the electron configuration of any element, given the total number of 
electrons in that element. 

• Be able to write either orbital representations or electron configuration codes. 

www.ckl2.org 92 



Lesson Vocabulary 

• electron configuration 

• diagonal rule 

• quantum number sum 



Strategies to Engage 

• Write ls 2 2s 2 2p 6 3s 2 3p 6 4s 2 on the board. Tell students that what you have just written is 
the electron configuration for Calcium, which shows the way the electrons are arranged 
in a Calcium atom. Ask students if they can figure out what the letters and numbers 
represent. Inform students that in this lesson they will not only learn what those letters 
and numbers represent, but they will also learn how to write the electron configuration 
for atoms of elements. 



Strategies to Explore 

• Emphasize for English Language Learners the figures in this lesson and use them to 
teach important concepts. Have a language proficient student "read" each visual, 
pointing out important concepts. (ELL) 



Strategies to Extend and Evaluate 

• Have students play a game of "electron configuration bingo". Instruct students to draw 
a five by five grid on a sheet of notebook paper and mark a "free space" in the middle. 
Have them write any of the first 24 elements in any order into the remaining spaces. 
Read electron configurations and have use a highlighter or pen to students mark off the 
elements it represents. The first student to correctly mark five elements horizontally, 
vertically, or diagonally wins. 



Have students research humorous stories about Wolfgang Pauli. Students should be 
prepared to share their findings with the class. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

93 www.ckl2.org 



Review Questions 

Have students answer the Lesson 7.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 7 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 7 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 94 



Chapter 8 

TE Electron Configurations and the Pe- 
riodic Table 



8.1 Unit 3 Periodic Relationships 
Outline 

This unit, Periodic Relationships, includes three chapters that explore the periodic table. 



• Chapter 8 Electron Configurations and The Periodic Table 

• Chapter 9 Relationships Between the Elements 

• Chapter 10 Trends on the Periodic Table 



Overview 

Electron Configuration and the Periodic Table 

This chapter develops the relationship between the electron configuration of atoms and their 
positions on the periodic table. 

Relationships Between the Elements 

This chapter introduces the chemical families caused by electron configuration, the concept 
of valence electrons, and Lewis electron dot formulas. 

Trends on the Periodic Table 

This chapter explains the periodic change in atomic size and its relationship to the periodic 
trends for ionization energy and electron affinity. 



95 www.ckl2.org 



8.2 Chapter 8 Electron Configurations and the Peri- 
odic Table 

Outline 

The chapter Electron Configurations and the Periodic Table consists of three lessons that 
explore the relationship between the electron configuration of an element and its position on 
the periodic table. 

• Lesson 8.1 Electron Configurations of Main Group Elements 

• Lesson 8.2 Orbital Configurations 

• Lesson 8.3 The Periodic Table and Electron Configurations 

Overview 

In these lessons, students will explore: 

• The relationship between the number of valence electrons an element has, and its 
position on the periodic table. 

• Hund's rule and then use it to write orbital representations for elements. 

• The relationship between an element's position on the periodic table and its atom's 
highest occupied energy level. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

• The Upper Limit of the Periodic Table 

The Periodic Table has been acknowledged as one of the most influential keys to understand- 
ing modern chemistry. A wealth of information is organized into a readily interpretable array 
of essential atomic data. Since the days of Dmitri Mendeleev, who is credited with arrang- 
ing our modern periodic table on the basis of physical similarities, atomic physicists have 
drastically extended the number of elements by the preparation of artificial elements. These 
are atoms not found naturally on Earth due to radioactive decay instability but have been 
created synthetically by atomic bombardment and collisions. 

The very first synthetic element was the result of many years of searching for the elusive 
missing element to be inserted between molybdenum and ruthenium, an omission noted and 

www.ckl2.org 96 



a space left open by Mendeleev. Many efforts claiming to have identified element #43 were 
made but not substantiated. Conclusive evidence for the production of a new element was 
made by Emilio Segre and Carlo Perrier in 1937 after they collided molybdenum atoms with 
the heavy isotope of hydrogen known as deuterium. Later trace amounts of technetium were 
identified among the decay products of uranium fission. The name technetium was chosen 
from the Greek word for artificial. 

The next synthetic element, #61, promethium, was produced by a similar method. Jakob 
Marinsky and Larry Glendenin at MIT bombarded neodymium atoms with neutrons ob- 
tained as byproducts of uranium decay. Their 1946 announcement named the new element 
after the mythological Prometheus, who, according to legend was responsible for bringing 
fire to mankind. 

The decade of the 1940's also marked the creation of the first trans-uranium element. Nep- 
tunium was the result of Berkeley scientists Edwin McMillan and Philip Abelson colliding 
uranium with neutrons as was the concurrent production of element 94, named plutonium 
in the sequence correlating with the modern group of solar system planets. One name sug- 
gested for element 94 was "extremium" offering the proposition that this artificially produced 
element was the upper limit or heaviest possible atom. 

Since that time, the quest for producing super-heavy elements has continued with the ques- 
tion of where and when that upper limit, if it exists, will be reached. Currently, (2009) 
the as- yet unnamed Element 118, a member of the noble gas family, maintains its status as 
the heaviest element. Three atoms of element 118 were reportedly created by fusing cali- 
fornium atoms with calcium atoms in 2006 at Lawrence Livermore Laboratory. In the last 
year, claims suggesting the existence of Element 122 have also been reported but as yet, 
experimental replications have failed to reproduce this evidence. 

Is there an upper limit to the periodic table? The intrinsic instability with respect to nuclear 
decay appears to limit the production of elements with atomic numbers greater than that 
of uranium. Most of the trans-uranium elements have extremely short half-lives and very 
limited production quantities. Attempting to load the tiny atomic nucleus with 100+ protons 
appears to provide a barrier that may have reached its synthetic limit. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Electron Config- 
urations and the Periodic Table. 

Class Periods per Lesson 



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Table 8.1: 



Lesson Number of 60 Minute Class Periods 



8.1 Electron Configurations of Main Group 1.0 
Elements 

8.2 Orbital Configurations 1.5 

8.3 The Periodic Table and Electron Con- 1.0 
figurations 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Electron Configurations and the Periodic Table. 

Electron Configurations and the Periodic Table Materials List 

Table 8.2: 

Lesson Strategy or Activity Materials Needed 

8.1 
8.2 
8.3 

Multimedia Resources 

You may find these additional web based resources helpful when teaching Electron Configu- 
rations and the Periodic Table: 

Interactive periodic table with basic information about each element http : //www . chemicalelements , 
com/ 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 



www.ckl2.org 98 



Standards Addressed by the Lessons in Electron Configurations and the 

Periodic Table 



Table 8.3: 

Lesson [California] Stan- [NSES] Standards [AAAS] Bench- 

dards marks 

8.1 Id 

8.2 Id 
8.3 



8.3 Lesson 8.1 Electron Configurations of Main Group 
Elements 

Key Concepts 

In this lesson, students explore the relationship between the number of valence electrons and 
element has and its position on the periodic table. 

Lesson Objectives 

• Explain how the elements in the Periodic Table are organized into rows and columns. 

• Explain how the electron configurations within a column are similar to each other. 

Lesson Vocabulary 

periodic table 
chemical properties 
valence electrons 
non-valence electrons 
alkali metals 
alkaline earth metals 
noble gases 

Strategies to Engage 

• Have students research the Hindenberg disaster of 1939. Point out to students that 
this disaster could have been avoided had the airship been filled with helium instead of 

99 www.ckl2.org 



hydrogen. Inform students that in this lesson, they will learn how electron configura- 
tions can be used to predict the properties of elements including their ability to react 
with each other. 



Strategies to Explore 

• This lesson provides the opportunity to introduce students to the concept of bonding. 
For example, when discussing the alkali metals, point out to students that they are 
very reactive. Ask them to come up with reasons as to why the alkali metals are so 
reactive. Don't be afraid to informally introduce the octet rule. 



Strategies to Extend and Evaluate 

• Have students write a matching quiz of the vocabulary explored in this lesson. Instruct 
students to trade quizzes with another student. Have students grade the quizzes in 
groups of four. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 8.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email request to teachers- 
requests@ckl2.org. 



8.4 Lesson 8.2 Orbital Configurations 
Key Concepts 

In this lesson students explore Hund's rule and use it to write orbital representations for 
elements. 

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Lesson Objectives 



Draw orbital diagrams. 

Define Hund's Rule. 

Use Hund's Rule to decide how electrons fill sublevels with more than one orbital. 



Lesson Vocabulary 

• orbital diagram 

• Hund's rule 



Strategies to Engage 

• Begin with a discussion of how electrons behave in atoms. Have each student write 
down five or six thoughts they may have about electrons and how they behave in atoms. 
Facilitate a discussion with students and address any misconceptions that may become 
evident at this time. 



Strategies to Explore 

Strategies to Extend and Evaluate 

• In order to assess student understanding, have them draw orbital diagrams that violate 
the Aufbau Principle, Pauli Exclusion Principle, and Hund's rule. Students should then 
explain each rule using their drawings. DI (ELL) 

• Challenge interested students to research the relationship between electron arrange- 
ment and the ability of some elements to behave as semiconductors. Students should 
be prepared to share their findings with the rest of the class. 

Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 8.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

101 www.ckl2.org 



Answers will be provided upon request. Please send an email request to teachers- 
requests@ckl2.org. 



8.5 Lesson 8.3 The Periodic Table and Electron Con- 
figurations 

Key Concepts 

In this lesson students explore the relationship between an element's position on the periodic 
table and its atom's highest occupied energy level. 

Lesson Objectives 

• Relate an element's position in the PT to the energy level of its valence electrons 
(excluding transition metals, lanthanides and actinides). 

• Relate an element's position in the PT to the sublevel of its highest energy valence 
electrons. 

• Explain why there are only two elements in the first row of the PT. 

Lesson Vocabulary 

transition metals 

lanthanides and actinides 

s sublevel block 

p sublevel block 

d sublevel block 

f sublevel block 

noble gases 

Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

Strategies to Explore 

• Have each student choose a group of main group elements. Instruct students to write 
the electron configuration for the first four elements in a vertical column and write down 

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two patterns they observe. They all have the same number of valence electrons. The 
energy level of the valence electrons increases as you go down the group of elements. 
Have students team up with classmates who have chosen a different group of elements 
and write down patterns they observe among the groups. The same patterns appear 
in each group. 

Strategies to Extend and Evaluate 

• Have students research and describe the physical properties of elements in their chosen 
group from the exploration section (above). Instruct students to write a short para- 
graph about the chemical similarities of the elements in the group and explain in terms 
of electron configuration, why the elements might have those properties. 

Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 8.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email request to teachers- 
requests@ckl2.org. 

Chapter 8 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 8 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



103 www.ckl2.org 



www.ckl2.org 104 



Chapter 9 

TE Relationships Between the Elements 



9.1 Chapter 9 Relationships Between the Elements 
Outline 

The chapter Relationships Between the Elements consists of six lessons that introduce the 
chemical families caused by electron configuration, the concept of valence electrons, and 
Lewis electron dot formulas. 



Lesson 9.1 Families on the Periodic Table 

Lesson 9.2 Electron Configurations 

Lesson 9.3 Lewis Dot Electron Diagrams 

Lesson 9.4 Chemical Family Members Have Similar Properties 

Lesson 9.5 Transition Elements 

Lesson 9.6 Lanthanide and Actinide Series 



Overview 

In these lessons, students will explore: 



The electron configurations of families of elements. 

A shortcut method for writing electron configurations. 

Electron dot diagrams. 

Trends in chemical reactivity within chemical families. 

Electron configurations of transition elements. 

The electron configurations of lanthanides and actinides. 



105 www.ckl2.org 



Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 



The Discovery of the Noble Gases 



The Group 8A elements are known both as the noble gases and with respect to their lack 
of reactivity, the inert gases. This unifying characteristic of this group of elements can be 
explained by the modern consideration of their electron configuration, specifically their filled 
valence shells. 

Their lack of participation in chemical reactivity and bonding hindered the progress of iden- 
tifying these elements. Although the first isolation of what ultimately become as argon was 
accomplished by Henry Cavendish in 1785, it was not conclusively shown to be a single type 
of atom until 1894. Cavendish removed the nitrogen, which he knew as "phlogisticated air" 
and oxygen, but noticed a persistent amount of residual gas. Rayleigh and Ramsay noticed 
discrepancies in the density of nitrogen gas measured by different mechanism and were the 
first to isolate a noble gas. For their efforts, each of them were awarded Nobel Prizes 

Despite its presence as the second most abundant element in the universe, the existence of 
the element helium was not suspected until 1868, when in the solar spectrum, emission lines 
were discovered by French astronomer Pierre Janssen which did not correspond to lines for 
any previously known elements. The unusual new substance was called helium because it 
was identified in the solar spectrum before it was found on Earth. William Ramsay was also 
involved in isolating helium, in this case from uranium salts treated with strong acid. Not 
long after Ramsay's work, Kansas geologists found an unidentifiable gas in the mixture from 
an oil-drilling operation, which was later measured to be helium. Currently, most available 
helium gas is obtained from extraction of natural gas. 

The discovery of the element neon, also credited to William Ramsay and Morris Travers, 
occurred with considerable excitement. This inert gas was obtained after removing nitrogen, 
oxygen and argon from a sample of liquefied air and his team happened to heat the residual 
gas sample. The gas unexpectedly yielded a bright red glow, now familiar as a neon sign. 

In the same series of experiments that produced neon, krypton and xenon were also identified 
by Ramsay and Travers in 1898. Krypton's name was borrowed for use in the comic books 
about Superman to designate the fictional substance that their hero was vulnerable to. 
Xenon, like the other members of this chemical family, remained characteristically inert 
until 1962, when chemist Neil Bartlett found that platinum hexafluoride salts react with this 
previously unreactive gas. Since that time, other compounds containing xenon have been 
prepared including Xenon tetroxide, Xe04 and xenon difluoride XeF2- A limited number of 
krypton compounds have also been reported such as KrF2. 

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The discovery of the remaining member of this chemical family, radon, was in part, the 
result of the research of Pierre and Marie Curie. They were responsible for isolating the 
radioactive elements polonium and radium. A German physicist, Friedrich Dorn, found that 
when radium is exposed to air, another radioactive gas was produced. This gas was further 
characterized by William Ramsay, who, in 1903 determined its atomic weight and suggested 
its placement among the noble gases. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 9. 
Class Periods per Lesson 

Table 9.1: 

Lesson Number of 60 Minute Class Periods 

9.1 Families on the Periodic Table 0.5 

9.2 Electron Configurations 0.5 

9.3 Lewis Electron Dot Diagrams 0.5 

9.4 Chemical Family Members Have Similar 0.5 
Properties 

9.5 Transition Elements 0.5 

9.6 Lanthanide and Actinide Series 0.5 

Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 9. 

Chapter 9 Materials List 

Table 9.2: 

Lesson Strategy or Activity Materials Needed 

9.1 Engagement Activity Index Cards 

9.4 Exploration Activity Graph Paper 



107 www.ckl2.org 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 9. 

• http : //dayah. com/periodic/ Interactive periodic table. 

• http://www.uky.edu/Projects/Chemcomics/ Periodic table of comic books. 

Possible Misconceptions 

Identify: Students may think that elements exist in their elemental state in nature. 

Clarify: A chemical element is a pure substance that consists of one type of atom. There 
are relatively few elements that exist in their elemental state. Most elements occur only in 
compounds with other elements. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standards Addressed by the Lessons in Chapter 9 

Table 9.3: 



Lesson 



Lesson 9.1 


la 


Lesson 9.2 




Lesson 9.3 


2c 


Lesson 9.4 


lg 


Lesson 9.5 




Lesson 9.6 


If 



California Stan- SSES Standards AAAS Standards 
dards 

la, lb, lc 



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108 



9.2 Lesson 9.1 Families on the Periodic Table 
Key Concepts 

In this lesson students explore the electron configurations of families of elements. 



Lesson Objectives 

• Describe the patterns that exist in the electron configurations for the main group 
elements. 

• Identify the columns in the periodic table that contain 1) the alkali metals, 2) the alka- 
line earth metals, 3) the halogens, and 4) the noble gases, and describe the differences 
between each family's electron configuration. 

• Given the outermost energy level electron configuration for an element, determine its 
family on the periodic table. 



Lesson Vocabulary 



group 

period 

alkali metals 

alkaline earth metals 

noble gases 

halogens 

main group elements 



Strategies to Engage 

• Have each student write the names and electron configurations of the first 18 elements 
on separate index cards. Instruct students to put the elements with the same number 
of valence electrons in the same column. Then ask them to move the elements that are 
in the same column so that the number of valence electrons increases from left to right. 
Next, instruct students to put the elements in the same row that contain the same 
number of energy levels. Then, ask them to arrange the elements so that the number 
of energy levels increases from top to bottom. Instruct students to compare their cards 
to the periodic table. Facilitate a discussion with students about the patterns that 
they have observed. 



109 www.ckl2.org 



Strategies to Explore 

• This lesson includes an introduction to several chemical families on the periodic table. 
Before reading, prepare less proficient readers by having students write the following 
on the top of separate sheets of notebook paper: 

1A 
2A 
5A 
6A 

7A 
8A 

As they read each section have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

Strategies to Extend and Evaluate 

• Have students create a photo album of one of the main group elements. Instruct 
students to include photos of the other elements in their chosen element's family. 

Review Questions 

Have students answer the Lesson 9.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



9.3 Lesson 9.2 Electron Configurations 
Key Concepts 

In this lesson students explore a shortcut method for writing electron configurations. 

Lesson Objectives 

• Convert from orbital representation diagrams to electron configuration codes. 
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Distinguish between outer energy level (valence) electrons and core electrons. 

Use the shortcut method for writing electron configuration codes for atoms and ions. 



Lesson Vocabulary 

• orbital box diagram 

• isoelectronic 

• core electrons 

• valence electrons 



Strategies to Engage 

• Write the electron configuration for barium on the board. Then write its electron 
configuration using the shortcut method. Ask students which they would prefer to 
write. Inform students that, in this lesson they will learn a shortcut method of writing 
electron configuration. Give students the opportunity to try to figure out the shortcut 
method. Tell them to "stay tuned" to see if they are correct. 



Strategies to Explore 

• You may want to spend time exploring the effect of adding electrons to and removing 
electrons from a neutral atom on its charge and the fact that an atom with a charge is 
called an ion. Students are often confused that adding an electron to a neutral atom 
results in an ion with a negative charge. Remind students that electrons are negative. 
You can point out this fact to students by using an analogy. Tell students, "suppose 
you have a group of friends and a few of those friends are negative. If you get rid of 
your negative friends, your group becomes more positive. If you add negative friends 
to your group, your group becomes more negative." 



Strategies to Extend and Evaluate 

• Have students play a review game called, "Two Truths and a Lie" using what they 
know about electron configuration. To do this, pair students, and have each pair write 
three statements, two of which are facts about electron configuration, and one of which 
is a plausible "lie." Then have each pair join with two other pairs to share what they 
wrote and try to guess which of the statements are "lies" and which are "truths." 

Ill www.ckl2.org 



Lesson Worksheets 

Copy and distribute the Lesson 9.2 worksheet named Electron Configuration in the 
Supplemental Workbook. Ask students to complete the worksheets alone or in pairs as a 
review of lesson content. 



Review Questions 

Have students answer the Lesson 9.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



9.4 Lesson 9.3 Lewis Electron Dot Diagrams 
Key Concepts 

In this lesson students explore electron dot diagrams. 

Lesson Objectives 

• Explain the meaning of an electron dot diagram. 

• Draw electron dot diagrams for given elements. 

• Describe the patterns of electron dot diagrams in the periodic table. 

Lesson Vocabulary 

• Lewis Electron Dot Diagram 

Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this lesson. 

Strategies to Explore 

• Have students choose a period of elements (except period 1) and draw the Lewis dot 
structure for each element in the period. Instruct them to write a paragraph explaining 

www.ckl2.org 112 



any patterns they observe. 



Strategies to Extend and Evaluate 

• Have students create a short lesson outlining how to write Lewis dot diagrams. En- 
courage students to create diagrams to include in the lesson. 



Lesson Worksheets 

Copy and distribute the four Lesson 9.3 worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 9.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



9.5 Lesson 9.4 Chemical Family Members Have Similar 
Properties 

Key Concepts 

In this lesson students explore trends in chemical reactivity within chemical families. 

Lesson Objectives 

• Explain the role of the core electrons. 

• Explain the role of valence electrons in determining chemical properties. 

• Explain how the chemical reactivity trend in a chemical family is related to atomic 
size. 

Lesson Vocabulary 

• noble gas core 

113 www.ckl2.org 



Strategies to Engage 

• Facilitate a discussion with students about family characteristics they share. Call on 
volunteers to share with the class any characteristics they may share with their family 
members. Tell students that in this lesson they will learn about characteristics, or 
properties shared by elements in the same family. 

Strategies to Explore 

• Have students create a graph of atomic number vs. atomic radius for elements 1-18. 
Facilitate a discussion with students about the patterns they observe. Within the same 
period, the atomic radius decreases as you move from left to right across the period. 
This is because there is an increase in the nuclear charge and an increase in the number 
of electrons in the same energy level. Increasing the amount of nuclear charge attracts 
the electrons closer to the nucleus. Within the same group, the atomic radius increases 
from top to bottom down the group. Although there is an increase in nuclear charge, 
adding another principal energy level results in the valence electrons being further from 
the nucleus 



Strategies to Extend and Evaluate 

• Have students choose a group of elements and write a fictional story entitled, "The 

Day the Disappeared", imagining if one day that family of elements 

were to disappear. Encourage students to be as creative as possible, but to include 
factual information about the uses of the elements in the group, and how life on Earth 
would be affected if that group were to disappear. 



Review Questions 

Have students answer the Lesson 9.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



9.6 Lesson 9.5 Transition Elements 
Key Concepts 

In this lesson students explore electron configurations of transition elements. 
www.ckl2.org 114 



Lesson Objectives 

• Define transition metals. 

• Explain the relationship between transition metals and the d sublevels. 

• State the periods that contain transition metals. 

• Write electron configurations for some transition metals. 



Lesson Vocabulary 

• transition metal 



Strategies to Engage 

• Ask students to identify the transition metals on the periodic table. Ask them to iden- 
tify some properties of transition metals. They are shiny, hard, dense, good conductors 
of heat and electricity, and have high melting points. 



Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI (LPR) 



Strategies to Extend and Evaluate 

• Have students research the use of transition metals in the creation of U.S. coins. Stu- 
dents should write a report that lists the transition metals that are found in each coin 
and why these metals are ideal for coins. 



Review Questions 

Have students answer the Lesson 9.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

115 www.ckl2.org 



9.7 Lesson 9.6 Lanthanide and Actinide Series 
Key Concepts 

In this lesson students explore the electron configurations of lanthanides and actinides. 

Lesson Objectives 

• Define the lanthanides and actinides. 

• Place the lanthanides and actinides in the periodic table. 

• Explain the importance of both the lanthanides and actinides. 

• Write electron configurations for lanthanides and actinides. 

Lesson Vocabulary 

• lanthanide 

• actinide 

Strategies to Engage 

• Students may wonder why the inner transition elements are often offset below the 
main body of the periodic table. Have them draw the block diagram located below the 
introduction paragraph to this lesson, but instruct them to place the lanthanides and 
actinides within the main body of the periodic table. Students should be able to see 
why the transition elements often appear below the main body of the periodic table. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students choose a lanthanide or actinide of interest to them. Instruct students to 
research their element's properties and history and create a resume for that element. 
Students may use the planning page found at http://www.nytimes.com/learning/ 
teachers/studentactivity/20090217.pdf to guide their research. 

Review Questions 

Have students answer the Lesson 9.6 Review Questions that are listed at the end of the 
lesson in their FlexBook. 



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Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 9 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 9 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



117 www.ckl2.org 



www.ckl2.org 118 



Chapter 10 



TE Trends on the Periodic Table 



10.1 Chapter 10 Trends on the Periodic Table 
Outline 

The chapter Trends on the Periodic Table consists of three lessons that explain the periodic 
change in atomic size and its relationship to the periodic trends for ionization energy and 
electron affinity. 

• Lesson 10.1 Atomic Size 

• Lesson 10.2 Ionization Energy 

• Lesson 10.3 Electron Affinity 

Overview 

In these lessons, students will explore: 

• the periodic trends in atomic size. 

• the trends in ionization energy and ionic size. 

• the trends in electron affinity. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

• The Chemistry of Glass 

119 www.ckl2.org 



In the world of the twenty-first century, it is difficult to imagine our day-to-day existence 
without glass. As a transparent material with great resistance to corrosive substance, it has 
many uses from container duty to its architectural impact as windows to its role in optical 
devices. Its versatility places glass in an indispensable position in our array of material 
choices. Glass is chemically defined as a member of a group of compounds that solidify from 
the molten state without crystallization. 

The original formulation of glass may have been based on observation of the naturally occur- 
ring opaque black glass known as obsidian, produced when volcanic lava is cooled abruptly 
by contact with water. Whether it was inspired or the result of a fortuitous accident, the first 
glasses originated in the Near East about 3000 B.C. Instructions for glassmaking have been 
identified on Mesopotamian cuneiform tablets. Their basic "recipe" included the same three 
main ingredients utilized to create modern glass formulations: formers, flux and stabilizers. 
A former is a material that forms the basis upon which the rest of the formulation is set; 
in many glasses, old and new, the former is silica, Si02, or sand. The flux is the substance 
added in a minor quantity mainly to lower the melting temperature of the mixture. Alkalis 
such as soda (sodium carbonate) and potash (potassium carbonate) have long been employed 
in this capacity. Lastly, the stabilizer, such as lime, CaO, calcium oxide, strengthens the 
glass and also adds water resistance. 

Various inorganic materials have been added to this classic formulation since antiquity and 
their incorporation has been shown to impart novel characteristics to the glass produced. 
One of the earliest substitutions seen in glass formulations include the addition of lead oxide 
as a flux material. Lead glass, which may have first been used in Han dynasty China, was 
shaped into artificial gemstones and later for lead crystal stemware. Lead glass has a lower 
melting temperature and a reputation for brilliance and sparkle due to its high refractive 
index. Lead glassware is also known for its ability to "ring" when struck that distinguishes 
from ordinary silicate glass. 

The addition of small amounts of various metal oxide salts to the basic glass formula produce 
"stained" glass, renowned in its use in churches and cathedrals. Cobalt oxide was responsible 
for the vivid blue coloration, red from gold salts and copper oxide imparted a brilliant green 
hue. 

The use of borax (boric oxide, B2O3) in place of soda and lime was a nineteenth century 
innovation attributed to Otto Schott, a German glassmaker, who originally called this new 
material "Duran". Borosilicate glass has a higher melting temperature and a much greater 
thermal stability. Its modern commercial name "Pyrex" is well known both to cooking 
enthusiasts and laboratory scientists. 

The underlying chemical rationale for the differing properties of these disparate glass formu- 
lations may be due to atomic size mismatches between the various components. Since glass 
is not a crystalline substance, without a regular, repeating microscopic structure, it is better 
represented as a disordered network with defects, or "empty spaces" in the network. The 
presence of atoms with variously sized atomic radii in these defect regions, can then alter the 

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macroscopic characteristics of the glass. For example, the substitution of the smaller boron 
atom in place of larger alkali metals may provide more efficient silica packing and possibly 
account for the enhanced thermal stability of Pyrex. Lead ions, more comparably sized to 
the alkali ions, present a glass product that has similar melting characteristics. 

What does the future hold for new glasses? Silicate fiber optics play a vital role in modern 
telecommunications. Heat resistant glasses are employed on the exterior of spacecraft for 
protection upon re-entry into Earth's atmosphere. Smart glass windows can control the 
amount of incoming solar radiation and there is research into "self-cleaning" window glass. 
Chicago's Sears Tower recently installed glass observation deck flooring with load-bearing 
tempered glass. The material that caught the eye and imagination of humans many years 
ago may have many more surprising applications in store. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 10. 
60 Minute Class Periods per Lesson 

Table 10.1: 



Lesson 



Number of Class Periods 



Lesson 10.1 Atomic Size 
Lesson 10.2 Ionization Energy 
Lesson 10.3 Electron Affinity 



0.5 

0.5 
0.5 



Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 10. 

Chapter 10 Materials List 

Table 10.2: 



Lesson 



Strategy or Activity 



Materials Needed 



Lesson 10.1 
Lesson 10.2 
Lesson 10.3 



121 



www.ckl2.org 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 10: 

Possible Misconceptions 

Identify: Students may think that the elements on the periodic table always follow the repeat- 
ing patterns in chemical and physical properties. Students may not know that the patterns 
illustrated by the periodic table are general trends, and that there are some exceptions. 

Clarify: Explain to students that the periodic table, arranged in order of increasing atomic 
numbers of the chemical elements reveals a tendency for the chemical and physical proper- 
ties of the elements to repeat in a periodic pattern. These periodic trends exist for many 
properties of the elements. Emphasize the use of the word "general" when describing the 
repeating patterns present in the periodic table. 

Promote Understanding: Create an element card for each of the first 18 elements. On 
each card write properties of the element such as boiling point, melting point, and density. 
Remove or cover all copies of the periodic table in the classroom. Give one set of cards 
to each group of three or four students. Instruct students to create their periodic table by 
arranging the cards according to the properties. Students should notice that they are able 
to arrange most of the elements in the correct order. 

Discuss: At the end of the lesson ask, What is the difference between the following two 
statements? 

• 1) The elements on the periodic table always follow the repeating patterns in chemical 
and physical properties. 

• 2) The elements on the periodic table have a tendency to follow repeating patterns in 
chemical and physical properties. 

The second statement leaves room for exceptions, while the first statement does not. 

Ask: Which of the two statements is a more correct description of the periodic table of 
elements? Explain. 

The second statement, because there are some exceptions to the periodic patterns. 

Ask: How can the second statement be stated differently? 

Sample answers: 

• 1) The elements on the periodic table generally follow repeating patterns in chemical 
and physical properties. 

www.ckl2.org 122 



Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 10 

Table 10.3: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

Lesson 10.1 lc 

Lesson 10.2 lc, 2g 

Lesson 10.3 lc, 2g 



10.2 Lesson 10.1 Atomic Size 
Key Concepts 

In this lesson students explore the periodic trends in atomic size. 

Lesson Objectives 

Define atomic radius. 

State the boundary issue with atomic size. 

Describe measurement methods for atomic size. 

Define the shielding effect. 

Describe the factors that determine the trend of atomic size. 

Describe the general trend in atomic size for groups and for periods. 

Describe the trend of atomic radii in the rows in the periodic table. 

Describe how the trend of atomic radii works for transition metals. 

Use the general trends to predict the relative sizes of atoms. 

Lesson Vocabulary 

• atomic size 

123 www.ckl2.org 



atomic radius 
nuclear charge 
shielding effect 
electron-electron repulsion 



Strategies to Engage 



Choose an element. Invite students to name three things they can predict about that 
element based on its position on the periodic table. Tell students that, in the next few 
lessons, they will learn how to predict even more information about an element based 
on its position on the periodic table. 



Strategies to Explore 

• Have groups of students come up with creative ways to act out the shielding effect and 
demonstrate for the other members of the class. DI (ELL) 



Strategies to Extend and Evaluate 

• Have students write a one-paragraph summary of this lesson. Inform students that 
they must include each of the vocabulary words in their summary. 



Lesson Worksheets 

Copy and distribute the Lesson X.x worksheets in the Supplemental Workbook. Ask students 
to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 10.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

www.ckl2.org 124 



10.3 Lesson 10.2 Ionization Energy 
Key Concepts 

In this lesson students explore the trends in ionization energy and ionic size. 



Lesson Objectives 

• Define ionization energy. 

• Describe the trend that exists in the periodic table for ionization energy. 

• Describe the ionic size trend that exists when elements lose one electron. 



Lesson Vocabulary 

• ionization energy 

• effective nuclear charge 

Strategies to Engage 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space in 
between. As you explore the lesson, have students write the "answer" to each objective. 

Strategies to Explore 

• Have groups of students come up with creative ways to act out effective nuclear charge 
and demonstrate for the other members of the class. DI (ELL) 

Strategies to Extend and Evaluate 

Have students find information on the properties of eight elements on the periodic table, one 
from each of the main groups. Have students write a short paragraph about each element, 
explaining, in terms of ionization energy, why their chosen elements might have the properties 
they do. 

Lesson Worksheets 

Copy and distribute the Lesson X.x worksheets in the Supplemental Workbook. Ask students 
to complete the worksheets alone or in pairs as a review of lesson content. 

125 www.ckl2.org 



Review Questions 

Have students answer the Lesson 10.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



10.4 Lesson 10.3 Electron Affinity 
Key Concepts 

In this lesson students explore the trends in electron affinity. 

Lesson Objectives 

• Define electron affinity. 

• Describe the trend for electron affinity on the periodic table. 

Lesson Vocabulary 

• electron affinity 

Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

Strategies to Explore 

• Outline the main concepts of the lesson as a class. Discuss the main concepts as you 
prepare the outline. 

Strategies to Extend and Evaluate 

• Have students record what they think is the main idea of each section. Have pairs 
of students come to a consensus on each main idea. Then, have each pair combine 
with another pair and again come to a consensus. Finally, have each group share their 
results with the class. DI (LPR) 

www.ckl2.org 126 



Lesson Worksheets 

Copy and distribute the Lesson X.x worksheets in the Supplemental Workbook. Ask students 
to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 10.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 10 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 10 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



127 www.ckl2.org 



www.ckl2.org 128 



Chapter 11 

TE Ions and the Compounds They Form 



11.1 Unit 4 Chemical Bonding and Formula Writing 
Outline 

This unit, Chemical Bonding and Formula Writing, includes five chapters that explore ionic 
and covalent bonds and naming and writing formulas for the resulting compounds. 

• Chapter 11 Ions and the Compounds They Form 

• Chapter 12 Writing and Naming Ionic Formulas 

• Chapter 13 Covalent Bonding 

• Chapter 14 Molecular Architecture 

• Chapter 15 The Mathematics of Compounds 

Overview 

Ions and the Compounds They Form 

This chapter explains the reasons for ion formation, ionic bonding, and the properties of 
ionic compounds. 

Writing and Naming Ionic Formulas 

This chapter develops the skills necessary to predict ionic charges, write ionic formulas, and 
name ionic compounds. 

Covalent Bonding 

This chapter explains the nature of the covalent bond, how and why covalent bonds form, 
which atoms form covalent bonds, and the nomenclature for binary covalent compounds. 

129 www.ckl2.org 



Molecular Architecture 

This chapter explains the formation of electronic and molecular geometries of covalent 
molecules including those that violate the octet rule. The chapter also develops the con- 
cept of polar molecules. 

The Mathematics of Compounds 

This chapter develops the skills involved in formula stoichiometry. 

11.2 Chapter 11 Ions and the Compounds They Form 
Outline 

The chapter Ions and the Compounds They Form consists of three lessons that explore the 
formation, structure, and properties of ionic compounds 

• Lesson 11.1 The Formation of Ions 

• Lesson 11.2 Ionic Bonding 

• Lesson 11.3 Properties of Ionic Compounds 

Overview 

In these lessons, students will explore: 

• why some atoms form negative ions while others form positive ions. 

• how electrons are transferred in the formation of ionic bonds. 

• the structure and properties of ionic compounds. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

• Softening Hard Water 

For centuries, mineral waters have been extolled for their health benefits and especially 
unique taste. Currently, there are thousands of different brands of bottled mineral waters. 
For readers who live in areas where water is obtained from ground wells, the complications of 
hard water are issues that they must contend with on a daily basis. Hard water is defined as 

www.ckl2.org 130 



water with an elevated amount of calcium and magnesium ions. The identity of the dissolved 
minerals is usually a function of the type of rock formations surrounding the wells. Areas 
containing deposits of limestone and dolomite nearby often have hard water because these 
types of rock contain calcium and magneisum ions than can be dissolved by ground water. 

With all the potential health benefits that hard water affords, why is it considered to be 
a problem? Hard water can shorten the lifetime of plumbing and render cleaning products 
less effective. The high mineral content of the water can result in certain salts, particularly 
carbonates, precipitating out of solution and generating scale. Scale or limescale, are the 
insoluble mineral deposits that can coat the interior of pipes, limiting their ability to transfer 
fluids by narrowing the passage. Scale also affects the utility of appliances that use water, 
such as water heaters, steam irons and coffee makers by leaving an unattractive white residue 
and clogging vents. Cleaning products produce less suds or bubbles in the presence of hard 
water because the Ca 2+ and Mg 2+ ions react with the organic fatty acids of the detergents 
and soaps, limiting their effectiveness. Soap scum is the product of this interaction and is 
characterized as the "bathtub ring". This ring will require more laborious scrubbing as it 
incorporates more greasy dirt. Personal care products like shampoos also do not lather very 
effectively in hard water. 

What can be done if you reside in a hard water area? Water softening is an available 
option to minimize the inconvenience of hard water. The method used to soften the water 
is to exchange the insoluble calcium and magnesium ions for the more universally soluble 
sodium ions. For this ion exchange, the hard water is passed through a bed containing an 
aluniinosilicate chemical matrix called a zeolite, upon which sodium ions have been deposited. 
The calcium and magnesium ions are trapped in the zeolite and the now-softened water has 
sodium ions as replacements. The system eventually becomes saturated with Ca 2+ and Mg 2+ 
ions and then must be regenerated by soaking in a strong brine solution. 

Some cautions do remain despite the widespread acceptance of this technology. Softened 
water has a high concentration of sodium ions, which have been linked with hypertension 
and its side effects. Patients with severe kidney disease should also probably avoid water 
softening. Other reports correlate water softening units with the weakening of beneficial 
bacteria that digest sewage in septic tanks. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 11. 
60 Minute Class Periods per Lesson 



131 www.ckl2.org 



Table 11.1: 



Lesson 



Number of Class Periods 



Lesson 11.1 The Formation of Ions 0.5 

Lesson 11.2 Ionic Bonding 0.5 

Lesson 11.3 Properties of Ionic Com- 0.5 
pounds 



Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 11. 

Chapter 11 Materials List 

Table 11.2: 



Lesson 



Strategy or Activity 



Materials Needed 



Lesson 11.1 

Lesson 11.2 
Lesson 11.3 



Possible Misconceptions 



Exploration Strategy 
Engagement Strategy 



Iron filings, powdered sulfur, 
Petri dish, Bunsen burner, 
magnet, metal rod 
Small objects such as gum 
drops, beans, or paper clips. 
Table salt, sugar, 2 beakers, 
conductivity tester 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 11: 



Printable periodic tables for handouts: http://science.widener.edu/~svanbram/ 

ptable.html 

Fill-in-the-blank worksheet generator: http : //www . theteacherscorner . net/printable-workshee 

make-your-own/f ill-in-the-blank/ 

Interactive lesson on chemical bonding: http: //www. visionlearning. com/library/ 

module_viewer . php?mid=55 

Interactive lesson on ionic bonding: http://www.teachersdomain.org/resource/ 

lsps07 . sci . phys . matter . ionicbonding/ 



www.ckl2.org 



132 



Possible Misconceptions 

Identify: Students may think that ionic compounds are formed spontaneously when a metal 
and a nonmetal come into contact with each other. 

Clarify: When a metal and a nonmetal come into contact with each other, they can physically 
combine to produce a mixture. 

Promote Understanding: Combine small amounts of sulfur and iron fillings in a Petri dish 
to produce a mixture. Run a magnet on the outside of the Petri dish to separate the iron 
from the sulfur without the sulfur becoming stuck to the magnet. Explain to students that 
the mixing of the iron and sulfur was not a chemical reaction because no new substances 
were formed. Re-combine the two elements into a glass dish or beaker in a fume hood. Use 
glassware that you don't mind ruining. Use a Bunsen burner to heat a metal rod and place 
it into the iron/sulfur mixture. The mixture will start to glow, and the elements will react 
to form iron(II) sulfide, a compound. The iron sulfide may become fused to the metal rod. 
Gases that are both toxic and corrosive could be produced, so perform this demonstration 
in a well-ventilated area. Explain to students that added heat caused a chemical reaction 
between the iron and the sulfur to occur. In this reaction a new substance -iron(II) sulfide- 
was formed. 



Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 11 

Table 11.3: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

Lesson 11.1 2c 

Lesson 11.2 2a, 2h 

Lesson 11.3 2c 



133 www.ckl2.org 



11.3 Lesson 11.1 The Formation of Ions 
Key Concepts 

In this lesson students explore why some atoms form negative while others form positive 
ions. 

Lesson Objectives 

• The student will define an ion. 

• The student will identify the atoms most likely to form positive ions and the atoms 
most likely to form negative ions. 

• The student will explain why atoms form ions. 

• The student will predict the charge on ions from the electron affinity, ionization ener- 
gies, and electron configuration of the atom. 

Lesson Vocabulary 

ion An atom or group of atoms with an excess positive or negative charge. 
cation a positive ion. 
anion a negative ion. 

Strategies to Engage 

• On the board or chart paper, write the octet rule (In reactions, atoms tend to lose, 
gain, or share electrons in order to have 8 valence electrons.) Have students write the 
electron configurations of each of the representative elements in period 3. Ask students 
to use the electron configurations and the octet rule to try to predict the number of 
electrons each element will gain or lose in chemical reactions. At the end of the lesson, 
have students see if their original answers were correct. 

Strategies to Explore 

• Hand each students a copy of the periodic table. As you explore this lesson, have 
students write the most probable ionic charges of the elements above each group of 
representative elements. 

www.ckl2.org 134 



• Point out in Figure 4 the division of the periodic table into metals and non-metals. 
Explain to students that metallic atoms tend to lose their electrons to form posi- 
tively charged cations and nonmetallic atoms tend to gain electrons to form negatively 
charged anions. 

• Play a game with the students. Write the names of 20 elements on chart paper or the 
board. Have students use the periodic table to write the most probable ionic charge 
for an atom of each element. The student who completes the list in the fastest amount 
of time wins! 

• Students often struggle with remembering that cations are positive and anions are 
negative. An easy way to distinguish and remember them is to look at the words 
themselves. Point out that the word "anion" can be read "a- negative-ion". The word 
cation can be read "c-a-positive ion". 

• Have students model the creation of ions of common elements such as fluorine, mag- 
nesium, sulfur, and potassium using small objects such as gum drops, beans, or paper 
clips. Instruct students to use the available objects to show that positive ions are 
formed by the loss of electrons and negative ions are formed by the gain of electrons. 
DI (ELL) 

Strategies to Extend and Evaluate 

• Have each student write five fill-in-the-blank statements with the blank at the end of 
the sentence about key concepts explored in this lesson. Have students exchange papers 
with another student who will try to complete the sentence by filling in the blank. Have 
them hand the papers back to the original student who will assign a grade. Encourage 
students to discuss any incorrect answers. Students can also generate fill-in-the-blank 
worksheets at: http : //www . theteacherscorner . net/printable-worksheets/make-your-own/ 
fill-in-the-blank/ 

• Have each student choose a different element and write down as much information they 
can about the element based on its position on the periodic table. Students should 
be prepared to share their information with the rest of the class. Possible information 
includes: atomic number; whether the element is a metal, nonmetal, or metalloid; most 
probable ionic charge, number of valence electrons, energy level of its valence electrons 
etc. 

Lesson Worksheets 

Copy and distribute the worksheet titled Ion Formation Worksheet and have the stu- 
dents complete the worksheet individually or in pairs. 

135 www.ckl2.org 



Review Questions 

Have students answer the Lesson 11.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



11.4 Lesson 11.2 Ionic Bonding 
Key Concepts 

In this lesson students explore how electrons are involved in the formation of ionic bonds. 

Lesson Objectives 

• The student will describe how atoms from an ionic bond. 

• The student will state why, in terms of energy, why atoms from ionic bonds. 

• The student will state the octet rule. 

• Given the symbol of a representative element, the student will indicate the most likely 
number of electrons the atom will gain or lose. 

• Given the electron configuration of a representative element, the student will indicate 
the most likely number of electrons the atom will gain or lose. 

• Given the successive ionization energies of a metallic atom, the student will indicate 
the most likely number of electrons the atom will lose during ionic bond formation. 

Lesson Vocabulary 

ionic bond A bond between ions resulting from the transfer of electrons from one of the 
bonding atoms to the other and the resulting electrostatic attraction between the ions. 

electrostatic attraction The force of attraction between opposite electric charges. 

Strategies to Engage 

• Review negative and positive ions and how they are formed. Students should recall 
that cations are formed from the loss of electrons by a neutral atom. Inform students 
that, in this lesson, they will learn what happens to these "lost" electrons". Students 
should also recall that anions are formed from the gain of electrons by a neutral atom. 
Inform students that, in this lesson, they will learn where these electrons come from. 



www.ckl2.org 136 



Strategies to Explore 

• Have students model the creation of ionic compounds such as sodium chloride, calcium 
fluorine, magnesium sulfide, and lithium oxide using small objects such as gum drops, 
beans, or paper clips. Instruct students to use the available objects to show the transfer 
of electrons in each compound. DI (ELL) 

Strategies to Extend and Evaluate 

• Have students write a creative personal ad for a representative element looking for a 
mate. Instruct students to include a picture and description of the element as well as 
a description of what the ion is looking for in a "mate". 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 11.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



11.5 Lesson 11.3 Properties of Ionic Compounds 
Key Concepts 

In this lesson students explore the structure and properties of ionic compounds. 

Lesson Objectives 

• The student will give a short, generic description of a lattice structure. 

• The student will identify distinctive properties of ionic compounds. 

Lesson Vocabulary 

Crystal lattice A systematic, symmetrical network of atoms forming an ionic solid. 

13 7 www.ckl2.ore 



Strategies to Engage 

• Sprinkle as small amount table salt from an unlabeled container into a beaker of water. 
Place the electrodes of a conductivity tester into the solution and plug it in. The bulb 
will glow. Sprinkle a small amount of sugar from an unlabeled container into a beaker 
of water. Place the electrodes of the conductivity tester into the solution. The bulb 
will not glow. Allow students the opportunity to offer a possible explanation. Explain 
to the students that the first compound was table salt, an ionic compound and the 
second substance was sugar, which is not ionic. Inform students as you explore this 
lesson they will be able to explain why the ionic compound caused the bulb to glow. 



Strategies to Explore 

• Have students write down the lesson objectives leaving five to ten lines of space in 
between. As you explore the lesson, encourage students to write the "answer" to each 
objecive. 



Strategies to Extend and Evaluate 

• Have each student choose an ionic compound to research and report on. Ask students 
to research information such as where the compound occurs naturally, what it is used 
for, and its properties. Students should be prepared to share their findings with the 
class. 



Ask students to look at Figure 14. Have them write a paragraph to describing the 
illustration in their own words. 



Lesson Worksheets 

Copy and distribute the four Lesson 11.3 worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 11.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



www.ckl2.org 138 



Chapter 11 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 11 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



139 www.ckl2.org 



www.ckl2.org 140 



Chapter 12 

TE Writing and Naming Ionic Formu- 
las 



12.1 Chapter 12 Writing and Naming Ionic Formulas 
Outline 

The chapter Writing and Naming Ionic Formulas consists of two lessons that develop the 
skills involved in predicting ionic charge, writing ionic formulas, and naming ionic com- 
pounds. 

• Lesson 12.1 Predicting Formulas of Ionic Compounds 

• Lesson 12.2 Inorganic Nomenclature 

Overview 

In these lessons, students will learn how to: 

• write formulas for ionic compounds. 

• name ionic compounds. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

• The History of Chemical Symbols 

141 www.ckl2.org 



The one or two letter shorthand used to represent chemical elements is a familiar feature in 
modern science. The tradition of using symbols to represent elements is quite ancient. Long 
before those interested in studying the composition and behavior of matter were known as 
chemists, mystical practitioners of alchemy devised symbols often to obfuscate their exper- 
imentation and to cloak their work in secrecy. Their coded imagery drew inspiration from 
astrology as well as ancient writing systems like the hieroglyphs. Alchemists linked certain 
metals with celestial bodies to describe their behavior, such as the connection between the 
rapidly moving planet Mercury and the metallic liquid quicksilver. 

As chemistry became an experimental science and new methods produced scores of newly 
discovered elements, the need for a shorthand technique to describe chemical changes became 
apparent. One of the first chemists to attempt to introduce a symbolic system for identifying 
the elements was John Dalton, known for his relative mass scale of the atomic weights. His 
symbols, introduced in 1808 in his "New System of Chemical Philosophy", consisted mainly 
of circles, some with inscribed alphabetic letters and others with dots or lines within the 
circles. Compounds were written as combinations of circles representing the constituent 
atoms. His system did not lend itself to ready memorization and did not catch on with his 
contemporaries. 

Our modern method of using one or two letter shorthand for the elements was devised in 
1813 by Jons Jakob Berzelius, citing the ease of implementation, particularly for typesetters. 
Due to the common employment of Latin terminology in scientific communication, Berzelius 
suggested using the first or first two letters of the element's Latin name as the symbol for 
that atom. In the case of confusion or duplication of the letters, exceptions includes the 
use of Hg (hydrargyrum for Mercury and plumbum for lead). Some modern modifications 
have been introduced for new elements, especially those named in honor of famous scientists. 
Berzelius is also responsible for the use of subscripts in a chemical formula to designate the 
ratio of atoms. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 12. 
60 Minute Class Periods per Lesson 

Table 12.1: 

Lesson Number of Class Periods 

Lesson 12.1 Predicting Formulas of Ionic 1.0 

Compounds 

Lesson 12.2 Ionic Nomenclature 1.0 



www.ckl2.org 142 



Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 12. 

Chapter 12 Materials List 

Table 12.2: 



Lesson 



Strategy or Activity 



Materials Needed 



Lesson 12.1 
Lesson 12.2 



Exploration Activity 



Index cards 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 12: 

• Writing the formulas of ionic compounds flowchart: http: //www.phs .princeton.kl2. 
oh . us/departments/Science/ldusch/honorspdf s/namingchpt5/Flowcharts . pdf 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 



Standard Addressed by the Lessons in Chapter 12 



Table 12.3: 

California Stan- NSES Standards AAAS 
dards marks 



Lesson 



Bench- 



Lesson 12.1 
Lesson 12.2 



143 



www.ckl2.org 



Apparently, the California standards do not list writing formulas or naming compounds 
as a standard. 



12.2 Lesson 12.1 Predicting Formulas of Ionic Com- 
pounds 

Key Concepts 

In this lesson students learn how to write formulas for ionic compounds. 



Lesson Objectives 

• Given the elements to be combined, the student will write correct formulas for binary 
ionic compounds, compounds containing metals with variable oxidation numbers, and 
compounds containing polyatomic ions. 



Lesson Vocabulary 

oxidation number The charge or apparent charge that an atom in a compound or ion 
would have if all the electrons in its bonds belonged entirely to the more electropositive 
atom. 



polyatomic ion An electrically charged species formed by covalent bonding of atoms of 
two or more different elements, usually non-metals. 



Strategies to Engage 

• Review with students how to determine the number of valence electrons and most 
probable ionic charge for representative elements based on their position on the periodic 
table. Explain to students that it is also possible to predict the formulas that result 
from the combination of elements based on their positions on the periodic table. Write 
the Ca and CI on the board. Ask students to try to predict the formula for the 
compound that would result from the combination of elements. Inform students that 
in this lesson they will learn how to do just that. 

www.ckl2.org 144 



Strategies to Explore 

• Give each student three index cards. Have each student label one index card with each 
of the following: binary ionic compounds, compounds containing metals with variable 
oxidation numbers, and compounds containing polyatomic ions. As you explore this 
lesson, have students write key points under each heading. This will give students a 
quick reference and help them to organize the information. 



Have students create flash cards with the name of the formula of a polyatomic ion on 
one side and its name on the other side. Encourage students to have friends and family 
members quiz them until they have memorized the ten most common polyatomic ions. 



Strategies to Extend and Evaluate 

• Have students create a short lesson on how to write formulas for ionic compounds. Tell 
students to include instructions on how to write formulas for: binary ionic compounds, 
compounds containing metals with variable oxidation numbers, and compounds con- 
taining polyatomic ions. 



Have students organize the information explored in this lesson into a flowchart that 
can be used to write the formula of an ionic compound given the atoms or polyatomic 
ions involved. An example is shown at : http://www.phs.princeton.kl2.oh.us/ 
department s/Science/ldusch/honorspdf s/namingchpt5/Flowcharts .pdf 



Lesson Worksheets 

Copy and distribute the Lesson 12.1 worksheets in the Supplemental Workbook (Formula 
Writing). Ask students to complete the worksheets alone or in pairs as a review of lesson 
content. 



Review Questions 

Have students answer the Lesson 12.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



145 www.ckl2.org 



12.3 Lesson 12.2 Inorganic Nomenclature 
Key Concepts 

In this lesson students explore naming ionic compounds. 



Lesson Objectives 

• Given the formula for a binary ionic compound, a compound containing metals with 
variable oxidation numbers, or a compound containing polyatomic ions, the student 
will name it. 

• Given the name for a binary ionic compound, a compound containing metals with 
variable oxidation numbers, or a compound containing polyatomic ions, the student 
will write the correct formula for it. 



Lesson Vocabulary 

anion An ion with a negative charge. 

cation An ion with a positive charge. 

chemical nomenclature The system for naming chemical compounds. 

ionic bond The electrostatic attraction between ions of opposite charge. 



polyatomic ion A group of atoms bonded to each other covalently but possessing an 
overall charge. 



Strategies to Engage 

• Write the following chemical formulas on the board: NaCl, K 2 SO&, and Fe20^. Asks 
students if they can correctly state the name of each compound. Ask any student who 
is able to provide the correct answer to explain how they were able to correctly name 
the compounds. Inform students that in this lesson they will learn how to name ionic 
compounds. 

www.ckl2.org 146 



Strategies to Explore 

• Give each student three index cards. Have each student label one index card with each 
of the following: binary ionic compounds, compounds containing metals with variable 
oxidation numbers, and compounds containing polyatomic ions. As you explore this 
lesson, have students write key points under each heading. This will give students a 
quick reference and help them to organize the information. 

Strategies to Extend and Evaluate 

• Have students create a short lesson on how to name ionic compounds. Tell students to 
include instructions on how to name: binary ionic compounds, compounds containing 
metals with variable oxidation numbers, and compounds containing polyatomic ions. 

• Have students organize the information explored in this lesson into a flowchart that 
can be used to name an ionic compound given the chemical formula. An example is 
shown at : http://www.phs .princeton.kl2.oh.us/departments/Science/ldusch/ 
honorspdf s/namingchpt5/Flowcharts . pdf 

Lesson Worksheets 

Copy and distribute the Lesson 12.2 worksheets in the Supplemental Workbook named In- 
organic Nomenclature. Ask students to complete the worksheets alone or in pairs as a 

review of lesson content. 



Review Questions 

Have students answer the Lesson 12.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 12 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 12 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 

147 www.ckl2.org 



www.ckl2.org 148 



Chapter 13 

TE Covalent Bonding 



13.1 Chapter 13 Covalent Bonding 
Outline 

The chapter Covalent Bonding consists of three lessons that explain the nature of the covalent 
bond, which atoms form covalent bonds, and the nomenclature rules for covalent compounds. 

• Lesson 13.1 The Covalent Bond 

• Lesson 13.2 Atoms that Form Covalent Bonds 

• Lesson 13.3 Naming Covalent Compounds 

Overview 

In these lessons, students will learn: 

• how and why covalent bonds form. 

• how to draw Lewis structures of molecules. 

• how to apply the IUPAC nomenclature system to name binary covalent compounds. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

• Organic Conductors 

149 www.ckl2.org 



Metallurgy was one of the first applied sciences to be mastered by humankind and successive 
generations have garnered increasing expertise in processing metal ores into many different 
versatile and valuable substances. Despite the overwhelming dependence of modern tech- 
nology on metals and their applications, new supplies of many different common metals 
have become increasingly more difficult to locate and procure. Many metals once considered 
plentiful are now deemed semi-precious and the possibility exists that we may be restricted 
to the reserves on hand in the future. 

The properties that make metals so valuable, such as their electrical and heat conductivity, 
malleability, hardness, and density are difficult to replicate in other materials. One attempt 
to retain the conductive characteristics of metals in more readily available materials is the 
development of organic conductors. Although most organic molecules are considered to be 
insulators, organic materials have been developed to produce semiconductors as well as truly 
conductive systems. 

The first organic conductors were constructed as charge transfer complexes; these systems 
consisted of two molecules with one acting as an electron donor and the other an electron 
acceptor. For example, tetracyanoquinodimethane (TCNQ) was first identified in 1962. As 
its structural formula indicates TCNQ contains alternating single, double and triple bonds 
and this structure readily accepts electrons while 



www.ckl2.org 150 





resulting in reallocation of the pi bonding electrons into new bonding arrangements. Sev- 
eral TCNQ complexes with a variety of electron donors, with high conductivities even into 
temperature ranges when the salt complexes melted. 

Organic conductors are compelling research targets due to the vast availability of the raw 
materials used to prepare them, and new research suggests the possibility of producing 
conductive biomaterials for medical applications. The graphene molecule has already been 
demonstrated to form attachments with nerve cells which display electrical conductance. 



151 



www.ckl2.org 




Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 13. 
60 Minute Class Periods per Lesson 

Table 13.1: 



Lesson 


Number of Class Periods 


Lesson 13.1 The Covalent Bond 


1.0 


Lesson 13.2 Atoms that Form Covalent 


1.5 


Bonds 




Lesson 13.3 Naming Covalent Compounds 


1.0 



Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 13. 

Chapter 13 Materials List 



www.ckl2.org 



152 



Table 13.2: 



Lesson Strategy or Activity Materials Needed 



Lesson 13.1 
Lesson 13.2 
Lesson 13.3 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 13: 

Possible Misconceptions 

Identify. Students may think a bond must be either ionic or covalent. 

Clarify: There is a continuum of ionic and covalent character that can be assigned to a bond. 
In other words chemical bonds can have characteristics along a continuum from an equal 
sharing of electrons to a complete transfer of electrons. If the bond involves two of the same 
atom (A-A), then the bond must be 100% covalent because neither atom has the ability to 
attract the electron pair more strongly than the other. However if the bond involves different 
atoms (A-B), the bond will have mixed covalent and ionic character. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 13 

Table 13.3: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

Lesson 13.1 2a 

Lesson 13.2 2b, 2e 

Lesson 13.3 2b 



153 www.ckl2.org 



13.2 Lesson 13.1 The Covalent Bond 
Key Concepts 

In this lesson students explore covalent bond formation. 

Lesson Objectives 

• The student will describe how covalent bonds form. 

• The student will explain the difference between ionic and covalent bond formation and 
structure. 

• The student will state the relationship between molecular stability and bond strength. 

Lesson Vocabulary 

covalent bond A type of chemical bond where two atoms are connected to each other by 
the sharing of two or more electrons in overlapped orbitals. 

covalent bond strength The strength of a covalent bond is measured by the amount of 
energy required to break the bond. 

Strategies to Engage 

• Review ionic bonding with students. Remind students that in ionic bonding, elec- 
trons leave metallic atoms and enter nonmetallic atoms. This complete transfer of 
electrons changes both of the atoms into ions. Inform students that, in this lesson, 
they will explore the bonding that occurs between nonmetallic atoms. Give students 
an opportunity to try to figure out how this type of bonding occurs. 

Strategies to Explore 

• Instruct students to summarize the information in the section called Molecular Stability 
into a table, concept map, or other diagram. 

Strategies to Extend and Evaluate 

• Outline the main concepts of the lesson as a class. Discuss the main concepts as you 
prepare the outline. 

www.ckl2.org 154 



• Read each statement in the lesson summary. Have students indicate whether or not 
they understand each statement by using thumb up/thumb down to show "Yes" or 
"No". Whenever a student uses a thumb down to show "No", use this as an opportunity 
to review this concept with the class. DI (ELL) 

Lesson Worksheets 

Copy and distribute the Lesson 13.1 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 13.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



13.3 Lesson 13.2 Atoms that Form Covalent Bonds 
Key Concepts 

In this lesson students explore Lewis structures of molecules. 

Lesson Objectives 

• The student will identify pairs of atoms that will form covalent bonds. 

• The student will draw Lewis structures for simple covalent molecules. 

• The student will identify sigma and pi bonds in a Lewis structure. 

Lesson Vocabulary 

covalent bond A type of bond in which electrons are shared by atoms. 
diatomic molecule A molecule containing exactly two atoms. 
double bond A bond in which two pairs of electrons are shared. 
triple bond A bond in which three pairs of electrons are shared. 

155 www.ckl2.org 



sigma bond A covalent bond in which the electron pair is shared in an area centered on 
a line running between the atoms. 



pi bond A covalent bond in which p orbitals share an electron pair occupying the space 
above and below the line joining the atoms. 



Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 



Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students create a picture dictionary for the six vocabulary words shown. They 
should draw their own illustrations to help explain the meaning of each term and write 
the definition under or beside the picture. DI (ELL) 



Have students choose the ten sentences from the text that most closely represent the 
main ideas of this lesson. Have them turn these sentences into a one-two paragraph 
summary of this lesson. 



Lesson Worksheets 

Copy and distribute the four Lesson X.x worksheets in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 13.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

www.ckl2.org 156 



13.4 Lesson 13.3 Naming Covalent Compounds 
Key Concepts 

In this lesson students learn the IUPAC nomenclature system for naming binary covalent 
compounds. 

Lesson Objectives 

• The student will name binary covalent compounds using the IUPAC nomenclature 
system. 

• The student will provide formulas for binary covalent compounds given the IUPAC 
name. 

Lesson Vocabulary 
Strategies to Engage 

• Write the following chemical formulas on the board: CO2, N 2 0^, and PC/3. Asks 
students if they can correctly state the name of each compound. Ask any student 
who is able to provide the correct answer to explain how they were able to correctly 
name the compounds. Inform students that in this lesson they will learn how to name 
covalent compounds. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students create a short lesson on how to name covalent compounds. 

Lesson Worksheets 

Copy and distribute the Lesson 13.3 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 13.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

157 www.ckl2.org 



Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 13 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 13 Assessment Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 158 



Chapter 14 



TE Molecular Architecture 



14.1 Chapter 14 Molecular Architecture 
Outline 

The chapter Molecular Architecture consists of five lessons that cover the electronic and 
molecular geometries of covalent molecules including those that break the octet rule and 
the theories involved in explaining them. The chapter also develops the concept of polar 
molecules. 

• Lesson 14.1 Types of Bonds that Form Between Atoms 

• Lesson 14.2 The Covalent Molecules of Family 2A-8A 

• Lesson 14.3 Resonance 

• Lesson 14.4 Electronic and Molecular Geometry 

• Lesson 14.5 Molecular Polarity 

Overview 

In these lessons, students will explore: 

• the relationship between electronegativity and bond type. 

• hybridization in various molecules. 

• resonance structures of covalent molecules. 

• the use of VSEPR theory in determining the molecular geometry of covalent com- 
pounds. 

• how to determine molecular polarity 

159 www.ckl2.org 



Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

• Chelates 

The expected shapes of molecules containing non-metal atoms can be predicted from Valence 
Shell Electron Pair Repulsion (VSEPR) Theory. The basis of this theory dictates that the 
optimal shape of the molecule maximizes the spatial distance between groups situated around 
a central atom. 

Metals also, may have groups oriented around them utilizing the same premises for assigning 
their shape. In the case of metal ions, the attached groups are usually referred to as ligands. 
When one ligand is attached to more than one site in the coordination sphere of the central 
metal, this is an example of a group known as a chelate. The term chelate comes from 
the Greek word "chele" meaning the claw, such as that of a crab or lobster. The ready 
attachment of these multidentate groups has been employed to extract the metal ion in 
certain situations, such as in what is known as chelation therapy. This technique is used to 
remove certain undesirable or toxic metal ions, such as lead or mercury ions from the body 
in cases of heavy metal poisoning. 

The first use of chelating agents was between the world wars as an antidote to the arsenic- 
based poisonous gas, Lewisite used on the battlefields of World War I. With what became 
known as British anti-Lewisite (BAL), a sulfur-based chelation agent was successfully applied 
to treat the gassing victims. In addition, the application of a chelate can be used to sequester 
metal ions such as radioactive thorium or plutonium for waste stream remediation. 

Chelates have also been used to stabilize metal ions and in some cases, improve their solubility 
as well. Gadolinium ions are desirable paramagnetic agents for use as contrast agents in 
Magnetic Resonance Imaging although the metal ions themselves have considerable toxicity. 
The use of DTPA (Diethylene triamine pentaacetic acid) has proved to be an effective agent 
for the enhanced solubility, improved biodistribution but most importantly, superior stability 
in vivo. Gd-DTPA contrast agents were approved for use in human MRI scans in 1988. 

Chelates have also been used in metalworking applications to control the availability of the 
metal ion; in many cases, chelates are used in place of other more toxic ligands, such as the 
cyanide ion. 

Metal chelates are also employed in agricultural applications to provide improved interaction 
of metal ions with soil components and also for better migration of the metal ion and therefore 
better distribution, particularly for those metal ions with important roles as macronutrients 
and micronutrients. 

One possible application of the use of chelates in medical treatment may be their use in the 
arteriosclerosis therapy. Research in progress utilizes chelates to sequester the calcium ions 

www.ckl2.org 160 



in arterial plaques. As calcium ions may serve as the binders that keep these plaques intact, 
the exploitation of the chelate effect may prove to be a key breakthrough in improving the 
longterm health of cardiac patients. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 14. 
60 Minute Class Periods per Lesson 

Table 14.1: 

Lesson Number of Class Periods 

Lesson 14.1 Types of Bonds that Form Be- 1.0 

tween Atoms 

Lesson 14.2 The Covalent Molecules of 1.0 

Family 2 A- 8 A 

Lesson 14.3 Resonance 1.0 

Lesson 14.4 Electronic and Molecular Ge- 2.0 

ometry 

Lesson 14.5 Molecular Polarity 1.0 

Managing Materials 

The following materials are needed to teach the strategies and activities described in the 
Teachers Edition of the FlexBook for Chapter 14. 

Chapter 14 Materials List 

Table 14.2: 

Lesson Strategy or Activity Materials Needed 

Lesson 14.1 Exploration Activity Index cards 

Lesson 14.2 

Lesson 14.3 

Lesson 14.4 Exploration Activity / Ex- 4 balloons, pin / Gumdrops, 

ploration Activity toothpicks 

Lesson 14.5 

161 www.ckl2.org 



Multimedia Resources 

You may find these additional Web-based resources helpful when teaching Chapter 14: 

• Lesson on Chemical Bonding http://www.visionlearning.com/library/module_ 
viewer . php?mid=55 

• Polar Bears and Penguins Bonding Activity http://www.keypress.com/Documents/ 
chemistry/SampleLessons/SmellsTG . pdf 

• Examples of polar and non-polar molecules http : //www . ausetute . com . au/molpolar . 
html 

• Tutorial on Drawing Resonance Structures http://www.chem.ucla.edu/~harding/ 
tutorials/resonance/draw_res_str . html 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 14 

Table 14.3: 



Lesson 




California 
dards 


Stan- 


NSES Standards 


AAAS 

marks 


Bench- 


Lesson 


14.1 


2a 










Lesson 


14.2 












Lesson 


14.3 












Lesson 


14.4 


2f 










Lesson 


14.5 


2f 











www.ckl2.org 162 



14.2 Lesson 14.1 Types of Bonds that Form Between 
Atoms 

Key Concepts 

In this lesson students explore the relationship between electronegativity and bond type. 

Lesson Objectives 

• Given binary formulas and an electronegativity chart, students will identify the most 
likely bonding type (ionic, covalent, or polar covalent) for each compound. 

• The student will describe a polar covalent bond and explain why it forms. 

Lesson Vocabulary 

bonding electron pair an electron pair found in the space between two molecules. 

electronegativity the tendency of an atom in a molecule to attract shared electrons to 
itself. 

octet rule the observation that atoms of non-metals tend to form the most stable molecules 
when they are surrounded by eight electrons (to fill their valence orbitals). 

polar covalent bond a covalent bond in which the electrons are not shared equally be- 
cause one atom attracts them more strongly that the other. 

Strategies to Engage 

• Students may recall that there are two types of compounds - ionic and molecular 
(covalent). Review the properties of these compounds. 

Strategies to Explore 

• Students can think of electronegativity as the "greediness" of an atom in a molecule. 
Some atoms are more "greedy" for the electrons in a bond, and tend to have higher 
electronegativity values. 

• Remind students that generally, electronegativity increases from bottom to top up a 
group and from left to right across a period on the periodic table. 

163 www.ckl2.org 



• Play a game with students. Cut 3x5 index cards in half. On the back of separate cards 
write the names and atomic numbers of the first 17 representative elements. On the 
front, write the electronegativity value of each element. Ask students to see if they 
can arrange the elements according to their positions in the periodic table using the 
electonegativity values only. Have them turn the cards over to see if their arrangements 
were correct. 

Strategies to Extend and Evaluate 

• Have students write a paragraph explaining Figure 3 in their own words. Instruct 
students to correctly use each vocabulary term at least once in their paragraph. 

Lesson Worksheets 

Copy and distribute the Lesson 14.1 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 14.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



14.3 Lesson 14.2 The Covalent Molecules of Family 2A- 

8A 

Key Concepts 

In this lesson students explore hybridization in various molecules. 

Lesson Objectives 

• Given binary formulas and an electronegativity chart, students will identify the most 
likely bonding type (ionic, covalent, or polar covalent) for each compound. 

• The student will draw Lewis structures for simple molecules that violate the octet rule. 

• Given a list of binary compounds, the student will identify those that require electron 
promotion in the explanation of their bonding. 

www.ckl2.org 164 



The student will identify the type of hybridization in various molecules. 
The student will explain the necessity for the concept of hybridized orbitals. 



Lesson Vocabulary 

hybrid orbitals a set of orbitals adopted by an atom in molecule different from those of 
the atom in the free state. 



hybridization a mixing of the native orbitals on a given atom to form special atomic 
orbitals for bonding. 



VSEPR model a model whose main postulate is that the structure around a given atom 
in a molecule is determined by minimizing electron-pair repulsion. 



Strategies to Engage 

• A hybrid is a combination of two or more different things. Before beginning this 
lesson, facilitate a discussion with students about different types of hybrids they may 
be familiar with in areas such as mythology, biology, music, computers, transportation, 
and even video games. 



Strategies to Explore 

• This lesson includes descriptions of covalent bonding that occurs in groups 3A-8A. 
Before reading, prepare less proficient readers by having students write the following 
on the top of separate sheets of notebook paper. Instruct students to write notes as 
they read each section. DI (LPR) 



The Covalent Bonds of Family 3A 
The Covalent Bonds of Family 4A 
The Covalent Bonds of Family 5A 
The Covalent Bonds of Family 6A 
The Covalent Bonds of Family 7A 
The Covalent Bonds of Family 8A 



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Strategies to Extend and Evaluate 

• Read each statement in the lesson summary. Have students indicate whether or not 
they understand each statement by using thumb up/thumb down to show "Yes" or 
"No". Whenever a student uses a thumb down to show "No", use this as an opportunity 
to review this concept with the class. DI (ELL) 

Lesson Worksheets 

Copy and distribute the Lesson 14.2 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 14.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



14.4 Lesson 14.3 Resonance 
Key Concepts 

In this lesson students explore resonance structures of covalent molecules. 

Lesson Objectives 

• The student will describe (chemistry) resonance. 

• The student will explain the equivalent bond strengths in a resonance situation. 

Lesson Vocabulary 

bond energy the energy required to break a given chemical bond. 

bond length the distance between the nuclei of the two atoms connected by a bond. 

resonance a condition occurring when more than one valid Lewis structure can be written 
for a particular molecule. The actual electronic structure is not represented by any 
one of the Lewis structures but by the average of all of them. 

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Strategies to Engage 

• Have a volunteer draw the Lewis structure of ozone (O3) on the board. Draw another 
Lewis structure of ozone next to it. Ask students to use a show of hands to indicate 
which is the correct Lewis structure. Draw brackets around each structure and a 
double arrow in between them. Point out to the students that the two structures are 
equivalent and that they are called resonance structures. Explain to students that in 
this lesson, they will explore resonance structures. 



Strategies to Explore 

• Emphasize for students that the way the term resonance used in chemistry has nothing 
to do with the way it is used in other disciplines and in everyday use. 



Strategies to Extend and Evaluate 

• On the board or chart paper, have students write a class summary of this lesson. Have 
one student come up with the first sentence and have student volunteers contribute 
sentences until the entire section has been summarized. 



Have students work in small groups to create a poster explaining the three resonance 
structures of carbon dioxide. Instruct students to include the three vocabulary terms 
on their posters. 



Lesson Worksheets 

Copy and distribute the Lesson 14.3 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 14.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



167 www.cki2.org 



14.5 Lesson 14.4 Electronic and Molecular Geometry 
Key Concepts 

In this lesson students explore the use of VSEPR theory in determining the molecular ge- 
ometry of covalent compounds. 

Lesson Objectives 

• The student will state the main postulate in VSEPR theory. 

• The student will identify both the electronic and the molecular geometry for simple 
binary compounds. 

Lesson Vocabulary 

unshared electron pair An unshared electron pair, also known as a non-bonding pair of 
electrons or as a lone pair of electrons, is two electrons in the same orbital in the outer 
shell of an atom that are not used in the formation of a covalent bond. 

electronic geometry The geometric arrangement of orbitals containing the shared and 
unshared electron pairs surrounding the central atom of a molecule or polyatomic ion. 

molecular geometry The specific three-dimensional arrangement of atoms in molecules. 

Strategies to Engage 

• Draw two models of water (H2O) on the board. Draw one with a bent shape and the 
other with a linear shape. Tell students that a water molecule has a bent, rather than 
linear shape. Explain to students that in this lesson they will learn how to determine 
the shapes of molecules. 

Strategies to Explore 

• Have students build molecules using gumdrops to represent atoms and toothpicks to 
represent the bonds between them. 

• Tie four balloons together. Use a pin to pop one balloon at a time to show how the 
shape changes from tetrahedral to trigonal planar to linear. Have students guess what 
the next shape will be each time a balloon is popped. 

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Strategies to Extend and Evaluate 

• Have students write a short lesson comparing and contrasting electronic and molecular 
structure. They should include specific examples and illustrations in the lesson. 

Lesson Worksheets 

Copy and distribute the Lesson 14.4 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 14.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

14.6 Lesson 14.5 Molecular Polarity 
Key Concepts 

In this lesson students explore how to determine molecular polarity. 

Lesson Objectives 

• The student will determine whether bonds are polar or non-polar. 

• The student will determine whether simple molecules are polar or non-polar. 

Lesson Vocabulary 

polar bond A covalent bond in which the shared pair of electrons are not shared equally 
owing to a difference in the electronegativity of the two atoms. 

molecular symmetry The property of a molecule that enables it to undergo inversion 
through a line, a point, or a plane, and its new state is indistinguishable from its 
original state. 

dipole A pair of equal and opposite charges separated by a small distance; a molecular 
dipole is produced when the centers of positive and negative charge do not coincide. 

169 www.ckl2.org 



Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this lesson. 

Strategies to Explore 

• Point out to students that if all of the bonds in a molecule are nonpolar, then the 
molecule itself is nonpolar. If the molecule has at least one polar bond, its polarity is 
determined by its shape. 

Strategies to Extend and Evaluate 

• Stand with your arms raised straight at your side so that you model a "t". Ask: If 
two people were pulling my hands with the same amount of strength, would I move? 
No. Move your arms forward slightly. Ask: Now, if two people were pulling my hands 
with the same amount of strength, would I move? Yes. Ask: In what direction would 
I move? Forward. Ask students to write a paragraph relating this demonstration to 
the concept of molecular polarity. Ask students to use each vocabulary term at least 
one time in their paragraph. 

• Have students organize the information explored in this lesson into a flowchart that 
can be used to determine if a molecule is polar or nonpolar. 

Lesson Worksheets 

Copy and distribute the Lesson 14.4 worksheets in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 14.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 14 Assessment 

Provided to teachers upon request at teachers-request@ckl2.org. 
www.ckl2.org I/O 



Chapter 14 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



171 www.ckl2.org 



www.ckl2.org 172 



Chapter 15 

TE The Mathematics of Compounds 



15.1 Chapter 15 The Mathematics of Compounds 
Outline 

The chapter The Mathematics of Compounds consists of four lessons that develop the skills 
involved in formula stoichiometry. 

• Lesson 15.1 Determining Formula and Molecular Masses 
. Lesson 15.2 The Mole 

• Lesson 15.3 Percent Composition 

• Lesson 15.4 Empirical and Molecular Formulas 

Overview 

In these lessons, students will explore: 

• Formula and molecular masses of compounds. 

• Calculations involving the mole. 

• The calculation of percent compositions given either the masses of the elements in a 
compound, or the chemical formula of a compound. 

• Empirical and molecular formula calculations. 

Science Background Information 

This material is provided for teachers who are just beginning to instruct in this subject area. 

173 www.ckl2.org 



• Avogadro's Number 

1811 was the year that Lorenzo Romano Amedeo Carlo Avogadro de Quaregna e di Cerreto 
- better known as Amedeo Avogadro, published his now famous hypothesis, it stated that 
equal volumes of gases contain the same number of particles. The nature of those particles 
was still a topic of considerable debate. Avogadro produced his theory based on the results 
of Joseph-Louis Gay-Lussac, who showed that when different gases combine, they do so in 
simple whole number ratios. His contemporary, John Dalton, responsible for the similar 
sounding Law of Multiple Proportions, reacted critically to Gay-Lussac's work. Dalton 
suggested that the atoms in gases were not capable of attaching; he argued that they would 
repel each other. Avogadro recognized that the viewpoints of both Dalton and Gay-Lussac 
could both be operable if, in his words, the same volume of gas contained the same number 
of molecules. It must be understood that the distinction between atoms and molecules did 
not exist in 1811 and the two words were used interchangeably. 

Avogadro's principle did not gain adherents until the concept of the atom became more solidly 
established. Likewise, the actual determination of what has become known as Avogadro's 
number, was not accomplished until after Avogadro's death in 1856. Johann Josef Loschmidt, 
an Austrian chemist, developed a method for the first estimate of the actual number. His 
technique entailed measuring the difference in volume between a given liquid substance, and 
the volume of that material upon evaporation into the gas phase. He reasoned that in the 
liquid phase, all of the liquid molecules touched their adjacent molecules and that there was 
no empty space. Thus the total volume of the liquid was equivalent to the volume of all of 
the liquid molecules added together. Comparing the volumes of the liquid and gas phases, 
he estimated that there were about 5 x 10 22 molecules in a volume of gas. By defining 
the number of molecules in a cubic meter of gas at standard temperature and pressure, he 
derived what is now known as "Loschmidt's number" or 2.686 x 10 25 . 

The establishment of a more carefully calculated value for the number of particles in one 
mole of any substance was made by Albert Einstein in the early twentieth century. Rather 
than using a gas model, Einstein's method was based on evaluating the number of sugar 
molecules in a sample of sugar water. His calculation was based on the average velocity that 
the individual molecules diffused through a membrane and was initially published as 2.1 x 
10 23 . Several years later, with new data from more accurate measurements, he redefined the 
value as 6.1 x 10 23 . 

The value now used in chemistry texts, 6.022 x 10 23 , was arrived at by a different technique. 
The current value has been calculated by using x-ray diffraction in crystal lattices of silicon 
atoms. 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 15. 
www.ckl2.org 174 



60 Minute Class Periods per Lesson 

Table 15.1: 



Lesson Number of Class Periods 



15.1 Determining Formula and Molecular 2.0 
Masses 

15.2 The Mole 2.0 

15.3 Percent Composition 1.5 

15.4 Empirical and Molecular Formulas 2.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chapter 15. 

Chapter 15 Materials List 

Table 15.2: 

Lesson Strategy or Activity Materials Needed 

15.1 
15.2 
15.3 
15.4 



Multimedia Resources 

You may find these additional web based resources helpful when teaching The Mathematics 
of Compounds: 



"Mole Day" activities: http://www.moleday.org/ 

Interactive mole quiz: http://glencoe. com/qe/science .php?qi=978 

Mole Conversion practice problem generator: http://science.widener.edu/svb/ 

tutorial/massmoles . html 

"Chemical Composition" flashcards: http: //college, cengage . com: 80/chemistry/ 

general/zumdahl/world_of _chem/le/students/f lashcards/ch06/index.html 



I/O www.ckl2.org 



Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 15 

Table 15.3: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

15.1 

15.2 3b, 3c, 3d 

15.3 3d 
15.4 

15.2 Lesson 15.1 Determining Formula and Molecular 
Mass 

Key Concepts 

In this lesson students explore formula and molecular masses of compounds. 

Lesson Objectives 

• When given the formula or name of a compound and a periodic table, the student will 
be able to calculate the formula mass. 

Lesson Vocabulary 

formula mass The sum of the atomic masses of the atoms in a formula. 

molecular mass The mass of a molecule found by adding the atomic masses of the atoms 
comprising the molecule. 

www.ckl2.org 17u 



Strategies to Engage 

• Review mass number and atomic number with students. Remind students that nearly 
the entire mass of an atom is determined by the protons and neutrons, and that the 
mass number of an atom is the sum of its protons and neutrons. Review with students 
how the atomic mass of an element is calculated by a weighted average of the atoms 
in a naturally occurring sample of the element. 



Write the atomic mass of ten different elements on the board. Time students as they 
locate the elements on the periodic table and write down the name, chemical symbol, 
and atomic number for each one. The student who completes the list in the fastest 
amount of time wins a prize. 



Strategies to Explore 

• Have students create a Venn diagram of formula mass vs. molecular mass. 



Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 



Strategies to Extend and Evaluate 

Lesson Worksheets 

Copy and distribute the Calculating Molar Mass Worksheet in the Supplemental Workbook. 
Ask students to complete the worksheet alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 15.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



177 www.ckl2.org 



15.3 Lesson 15.2 The Mole 
Key Concepts 

In this lesson students explore calculations involving the mole. 

Lesson Objectives 

• Given the number of particles of a substance, the student will use Avogadro's number 
to convert to moles and vice versa. 

• Given the number of moles of a substance, the student will use the molar mass to 
convert to grams and vice versa. 

Lesson Vocabulary 

Avogadro's number The number of objects in a mole; equal to 6.02 x 10 23 . 
mole An Avogadro's number of objects. 

Strategies to Engage 

• Explain to students that in this lesson, they will be introduced to the mole, which 
is the SI unit that describes the amount of a substance. Write Avogadro's number 
in standard form on the board. If students comment that the mole is a very large 
quantity, remind them that atoms are incredibly tiny. Tell students that just as a 
dozen eggs is 12 eggs, a mole of eggs is 6.02 x 10 23 eggs. 

Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• Encourage interested students to research the work of Amedeo Avogadro and his con- 
tributions to chemistry. Students should be prepared to share their findings with the 
class. 

www.ckl2.org 1/8 



Have students create a "mole hill" and display it on a wall of the classroom. Have 
each student contribute two or three quantities that are equal to a mole such as 32.1 
g of sulfur, 18.0 g of water, or 34.0 g of hydrogen peroxide. Collect the students' 
contributions and use them to create a "mole hill". You may want to ask a student to 
draw a large mole (the animal) to sit on top of the hill. 



Lesson Worksheets 

Copy and distribute the Moles Worksheet in the Supplemental Workbook. Ask students to 
complete the worksheet alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 15.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



15.4 Lesson 15.3 Percent Composition 
Key Concepts 

In this lesson students explore the calculations of percent composition given either the masses 
of the elements in a compound or the chemical formula of a compound. 



Lesson Objectives 

• Given either masses of elements in a compound, the student will calculate the percent 
composition by mass. 

• Given the formula or name of a compound, the student will calculate the percent 
composition by mass. 



Lesson Vocabulary 

percent composition The proportion of an element present in a compound found by 
dividing the mass of the element by the mass of the whole compound and multiplying 
by 100. 



179 www.ckl2.org 



Strategies to Engage 

• Students are asked how they would determine the percentage of males and females in 
the classroom? Count the number of males and the number of females. Add them up, 
then divide the number of males by the total, and the number of females by the total. 
Then, multiply each by 100. Explain to students that in this lesson they will explore 
percent composition, which is the percent by mass of each element in a compound. It 
is calculated in much the same way. 



Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 



Strategies to Extend and Evaluate 

• Ask small groups of students to write a four-step method of calculating percent com- 
position. Choose the best set of steps out of all of the groups. Write the steps on the 
board, and use those steps to complete practice and review problems. 



Write the formulas for different compounds on strips of paper and place them in a 
hat or container. Have students draw the formulas and then calculate the percent 
composition of the compound they have drawn. 



Lesson Worksheets 

Copy and distribute the Percent Composition Worksheet in the Supplemental Workbook. 
Ask students to complete the worksheet alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 15.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



www.ckl2.org 180 



15.5 Lesson 15.4 Empirical and Molecular Formulas 
Key Concepts 

In this lesson students explore empirical and molecular formula calculations. 

Lesson Objectives 

• The student will reduce molecular formulas to empirical formulas. 

• Given either masses or percent composition of a compound, the student will determine 
the empirical formula. 

• Given either masses or percent composition of a compound and the molar mass, the 
student will determine the molecular formula. 

Lesson Vocabulary 

empirical formula The formula giving the simplest ratio between the atoms of the ele- 
ments present in a compound. 

molecular formula A formula indicating the actual number of each kind of atom con- 
tained in a molecule. 

Strategies to Engage 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space 
in between. As you explore the lesson, have students write specific examples of each 
objective. 

Strategies to Explore 

• Have students create a Venn diagram of empirical formula vs. molecular formula. 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• Have students create study cards of the calculations explored in this chapter. 

181 www.ckl2.org 



Lesson Worksheets 

Copy and distribute the Empirical Formulas and Molecular Formulas Worksheets in the 
Supplemental Workbook. Ask students to complete the worksheets alone or in pairs as a 
review of lesson content. 



Review Questions 

Have students answer the Lesson 15.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 15 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 15 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 182 



Chapter 16 



TE Chemical Reactions 



16.1 Unit 5 Reactions and Stoichiometry 
Outline 

This unit, Reactions and Stoichiometry, includes two chapters that introduce students to 
chemical reactions, chemical equations, and stoichiometric relationships. 

• Chapter 16 Chemical Reactions 

• Chapter 17 Mathematics and Chemical Equations 

Overview 

Chemical Reactions 

This chapter develops the skills involved in mass and molecule to mole calculations and the 
determination of reaction types. 

Mathematics and Chemical Equations 

This chapter develops the skills involved in equation stoichiometry including limiting reactant 
equations, yields, and introduces heat of reaction. 

16.2 Chapter 16~"0303Chemical Reactions 

The chapter Chemical Reactions consists of three lessons that develop the skills involved in 
mass and molecule, to mole calculations and the determination of reaction types. 

183 www.ckl2.org 



• Lesson 16.1 Chemical Equations 

• Lesson 16.2 Balancing Equations 

• Lesson 16.3 Types of Reactions 

Overview 

In these lessons, students will explore: 

• The symbol equations and word equations used to describe chemical reactions. 

• The balancing of chemical equations. 

• Different types of chemical reactions. 

Science Background Information 

Fireworks 



www.ckl2.org 184 



185 www.ckl2.org 



Table 16.1: (continued) 



Table 16.1: 



If you enjoyed a Fourth 
of July evening pyrotech- 
nic display, or perhaps wit- 
nessed a New Years' Eve 
event, you've witnessed the 
results of over a thousand 
years' worth of research and 
development into the art of 
fireworks. The first efforts 
were produced in China ini- 
tially by accident as they ob- 
served that when saltpeter 
(potassium nitrate, KNO3) 
was dropped into a charcoal 
fire, the mixture "popped" 
and produced an interesting 
flame color. Later, as a 
means to surprise their en- 
emies in battle, the earli- 
est "Shock and Awe" cam- 
paigns featured a mixture 
of saltpeter, charcoal and 
sulfur. The mechanism by 
which fireworks operate in- 
volves heating the proper ra- 
tio of these materials (75% 
KNO3, 15% carbon and 10% 
sulfur), and generating a 
chemical reaction to produce 
nitrogen and carbon dioxide 
gases. These initial "gung 
pow" were mainly explo- 
sive devices directed into the 
air, but later new additions 
brought whistling sound ef- 
fects and a spectrum of col- 
ors to dazzle their oppo- 
nents. The energy needed to 
propel the shell and to ex- 
cite the composite atoms is 
wBSW.cpkbS-iid^l by a gunpow- 
der formula. 




(Source: http: 

//commons . wikimedia . 
org/wiki/File : 
200508-DSCN0417Fireworks . 
jpg, Author: Semnoz, Li- 
cense: CC-BY-SA 3.0) 



186 



Table 16.1: (continued) 



The brilliant colors that produce the oohs and aahs of today's displays are mainly due to 
elements like magnesium, which results in a blinding white effect. On an atomic level, the 
energy imparted by the explosion causes the atom's electrons to be promoted to a higher 
energy level. When the atoms relax back to the ground state, a specific amount of energy 
is released and the color of visible light reveals the frequency of light corresponding to that 
energy value. The red coloration is due to the presence of lithium or strontium salts such 
as lithium or strontium carbonate. Sodium salts (usually nitrate) generate a yellow hue 
and calcium chloride or sulfate result in orange coloration. Barium chloride supplies a green 
color. The all- American red, white and blue display is difficult to construct due to the 
complexity of finding a blue colored explosive. Usually copper chloride in a blue- violet hue is 
substituted. This copper salt's instability at the high temperatures of the exploding device 
has caused modern day pyrotechnical researchers to continue the search for a reliable source 
of blue color. 

The shape of the image produced when the shell explodes in the air is a function of how 
the components are arranged in the shell. When the pyrotechnic device explodes as the 
resultant gases are produced, the arrangement of the salts in the mortar shell will mirror the 
pattern produced by the explosion. Dividing the materials into different compartments can 
also produce a "time - delay" effect, where the display effects occur sequentially. 

The sound effects employed as a counterpoint to the visual display are also the result of 
chemical reactions. Adding bismuth trioxide to the mixture generates "popping" noises, 
whereas copper salicylate yields a "whistling" sound. 

On the next occasion when a fireworks display rises to the sky, you'll not only enjoy the 
beautiful visual effects, but have an appreciation for the science that went into the presen- 
tation. 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 16. 
60 Minute Class Periods per Lesson 

Table 16.2: 
Lesson Number of Class Periods 



16.1 Chemical Equations 0.5 

16.2 Balancing Equations 2.0 

16.3 Types of Reactions 2.0 



1ST www.ckl2.org 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chemical Reactions. 

Chapter 16 Materials List 

Table 16.3: 

Lesson Strategy or Activity Materials Needed 

16.1 
16.2 
16.3 Extension Activity Index cards 

Multimedia Resources 

You may find these additional web based resources helpful when teaching Chemical Reactions: 

• Balancing chemical equations activity: http : //www . middleschoolscience . com/balance . 
html 

• Balancing chemical equations game: http : //f unbasedlearning . com/chemistry/chemBalancer/ 
default .htm 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 16 



www.ckl2.org 188 



Table 16.4: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



16.1 3a 

16.2 3a 
16.3 



16.3 Lesson 16.1 ~"0303Chemical Equations 



Key Concepts 

In this lesson, students will explore the word equations and symbol equations that chemists 
use to describe chemical reactions. 

Lesson Objectives 

• The student will read chemical equations, and provide requested information contained 
in the equation including information about substances, reactants, products, and phys- 
ical states. 

• The student will convert symbolic equations into word equations and vice versa. 

• The student will use the common symbols, +, (s), (L), (g), (aq), and — > appropriately. 

• The student will describe the roles of subscripts and coefficients in chemical equations. 

• The student will balance chemical equations with the simplest whole number coeffi- 
cients. 



Lesson Vocabulary 

reactants:The substances on the left side of a chemical equation. 
products:The substances on the right side of a chemical equation. 
(s):As a subscript to a formula, indicates the substance is in the solid phase. 
(L):As a subscript to a formula, indicates the substance is in the liquid phase. 
(g):As a subscript to a formula, indicates the substance is in the gaseous phase. 
(aq):As a subscript to a formula, indicates the substance is dissolved in water. 

Strategies to Engage 

• Review with students the difference between physical and chemical changes. Remind 
students that in a chemical change (reaction) new substances are formed. These new 

189 www.ckl2.org 



substances have different properties than the original substance. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have each student bring in an example of a chemical reaction that they see in everyday 
life. Have each student identify the products, reactants, and physical states of all 
substances involved and discuss these with the class. 



Have students write the equation for the reaction of solid sodium bicarbonate with 
hydrochloric acid to produce aqueous sodium chloride, water, and carbon dioxide gas. 
Have them label each vocabulary word in the appropriate place in the equation. 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 16.1 Review Questions that are listed at the end of the 
lesson in their Flexbook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

16.4 Lesson 16.2 ~"0303Balancing Equations 
Key Concepts 

In this lesson students will learn to balance non-redox chemical equations. 



Lesson Objectives 

• Demonstrate the Law of Conservation of Matter in a chemical equation. 

• Explain the roles of coefficients and subscripts in a chemical equation. 

• Balance equations using the simplest whole number coefficients. 

www.ckl2.org 190 



Lesson Vocabulary 

• law of conservation of matter:Matter is neither created nor destroyed in chemical 
reactions. 

• skeletal equation:A chemical equation before it has been balanced. 

• balanced chemical equation:A chemical equation in which the number of each type 
of atom is equal on the two sides of the equation. 

Strategies to Engage 

• Review with students the Law of Conservation of Matter. Explain to students that in 
this lesson they will demonstrate the relationship of this law to chemical equations. 

Strategies to Explore 

• Have students create a Venn diagram comparing and contrasting coefficients and sub- 
scripts. 

Strategies to Extend and Evaluate 

• Divide students into groups of four. Within each group of four, have pairs of students 
take turns coming up with equations for the other pair of students to balance. 

• Have interested students develop a way to teach younger kids how to balance equations 
using candies or other small objects. Students should be prepared to demonstrate their 
method in front of the class using real examples. 

Lesson Worksheets 

Copy and distribute the worksheet titled Balancing Equations. Ask students to complete 
the worksheet alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 16.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

191 www.ckl2.org 



16.5 Lesson 16.3~"0303Types of Reactions 
Key Concepts 

In this lesson, students will learn to identify the different types of chemical reactions. 

Lesson Objectives 

• Identify the types of reactions. 

• Predict the products in different types of reactions. 

• Distinguish between the different types of reactions. 

• Write balanced chemical equations and identify the reaction type given only the reac- 
tants. 

Lesson Vocabulary 

• synthesis:A synthesis reaction is one in which two or more reactants combine to make 
one type of product. (A + B — > C). 

• decomposition^ decomposition reaction is one in which one type of reactant breaks 
down to form two or more products. (C — > A + B). 

• single replacement (metal) :In a single replacement (metal) reaction, one element 
replaces the metal cation of the compound reactant to form products. (A + BC — > 

AC + B). 

• single replacement (many metals with acid):In a single replacement (many metals 
with acid) reaction, one element replaces the hydrogen cation of the compound (which 
is an acid) reactant to form products. Example: A + 2 HC — » AC 2 + H 2 . 

• single replacement (non-metal): In a single replacement (non-metal) reaction, one 
element replaces the non-metal (anion) of the compound reactant to form products. 

(XY + Z ^ XZ + Y). 

• double replacement :For double replacement reactions two reactants will react by 
having the cations replace the anions. (AB + XY — ► AY + XB). Double replacement 
reactions are also called metathesis reactions sometimes. 

• combustion (complete) :Combustion is the burning in oxygen, usually a hydrocar- 
bon. ( fuel + 2 -> C0 2 + H 2 0). 

www.ckl2.org 192 



• combustion (incomplete) incomplete combustion is the inefficient burning in oxy- 
gen, usually a hydrocarbon. Inefficient burning means there in not enough oxygen to 
burn all of the hydrocarbon present, sometimes carbon (soot) is also a side product of 
these reactions. ( fuel + O2 — > CO2 + H 2 0). 

• hydrocarbons: Compounds containing hydrogen and carbon. 

Strategies to Engage 

• Before beginning this lesson, write four or five of the sample questions found in the stu- 
dent book that require students to predict the products of chemical reactions. Explain 
to students that by the end of this lesson, they will be able to predict the products of 
these and other chemical reactions. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students write each of the five types of reactions explored in this lesson on separate 
index cards. Have groups of students take turns picking a card and acting out the type 
of reaction on the card, using props if necessary, while the others guess which one it is. 

• As a review of the chapter vocabulary, suggest that students make flash cards, with 
the vocabulary term on one side, and a definition and example of it on the other. 

• Have students make a poster of each of the types of chemical reactions explored in this 
chapter. Ask students to find specific examples of each reaction. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 16.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



193 www.cki2.0rg 



16.6 Chapter 16 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 16 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 194 



Chapter 17 

TE Mathematics and Chemical Equa- 
tions 



17.1 Mathematics and Chemical Equations 
Outline 

The chapter Mathematics and Chemical Equations consists of five lessons that develop the 
skills involved in equation stoichiometry including limiting reactant equations, yields, and 
introduces heat of reaction. 

. Lesson 17.1~"0303 The Mole Concept and Equations 

. Lesson 17.2~"0303 Mass-Mass Calculations 

• Lesson 17.3~"0303 Limiting Reactant 
. Lesson 17.4~"0303 Percent Yield 

• Lesson 17.5~"0303 Energy Calculations 

Overview 

In these lessons, students will explore: 

• Mole relationships in balanced chemical equations. 

• Mass relationships in balanced chemical equations. 

• Limiting and excess reactants in chemical reactions. 

• Theoretical, actual, and percent yield of a product. 

• Energy changes in chemical processes. 

195 www.ckl2.org 



Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Excess and Limiting Reactants 

The chemical name for chalk is calcium carbonate. The reaction between sodium carbonate 
and calcium chloride produces calcium carbonate. 

Na 2 C0 3 (a q ) + CaCl 2(aq) -► CaC0 3 ( s ) + 2 NaCl (aq) 

Stoichiometry allows us to compare the amounts of various species involved in a reaction. 
In order to determine which of the reactants is the limiting reactant, we must take into 
account both the amounts present and how they relate stoichiometrically in the balanced 
equation. Why do chemists use limiting reactants? The reason lies in the fact that not 
all reactions go to 100% completion; in fact the majority of the really interesting ones do 
not. However, scientists can use an equilibrium "trick" to get the stubborn reactions to go 
to completion. They start with an excess of one of the reactants to "push" the reaction to 
make more product. This essentially makes the other reactant the limiting reactant. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Mathematics and 
Chemical Equations . 

60 Minute Class Periods per Lesson 

Table 17.1: 

Lesson Number of Class Periods 

17.1 The Mole Concept and Equations 1.0 

17.2 Mass-Mass Calculations 2.0 

17.3 Limiting Reactant 1.5 

17.4 Percent Yield 1.5 

17.5 Energy Calculations 1.5 



www.ckl2.org 196 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Mathematics and Chemical Equations . 

Mathematics and Chemical Equations Materials List 

Table 17.2: 

Lesson Strategy or Activity Materials Needed 

17.1 

17.2 

17.3 Engagement Strategy 5 plates, 4 forks, 4 knives, 

and 3 spoons 

17.4 

17.5 Engagement Strategy 2-50 mL beakers, 2 g of 

NaOH, 2 g of NaHC0 3 , 2 
thermometers 

Multimedia Resources 

You may find these additional web based resources helpful when teaching Mathematics and 
Chemical Equations . 

• Stoichiometry game: http://www.chemcollective.org/mr/ 

• Humorous "Mole" Video: http://www.youtube . com/watch?v=lR7NiIum2TI 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Mathematics and Chemical Equa- 
tions 

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Table 17.3: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



17.1 3c, 3e 

17.2 3e 

17.3 3e 

17.4 3f 
17.4 7b 



17.2 Lesson 17.1 ~"0303The Mole Concept and Equa- 
tions 

Key Concepts 

• In this lesson, students will explore mole relationships in balanced chemical equations. 



Lesson Objectives 

• Express chemical equations in terms of molecules, formula units, and moles. 

• Determine mole ratios in chemical equations. 

• Explain the importance of balancing equations before determining mole ratios. 

• Use mole ratios in balanced chemical equations. 



Lesson Vocabulary 

chemical coefficient The number in front of a molecule's symbol in a chemical equation 
indicates the number molecules participating in the reaction. If no coefficient appears, 
we interpret it as meaning 1. 



formula unit The empirical formula of an ionic or covalent compound. 



stoichiometry The calculation of quantitative relationships of the reactants and prod- 
ucts in a balanced chemical reaction. Sometimes it is called reaction stoichiometry to 
distinguish it from composition stoichiometry 



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Strategies to Engage 

• Review balancing equations by having students write the steps to balancing equations 
on the board. Students then use the steps to balance an actual equation. 



Review with students that a balanced equation has numbers called coefficients in front 
of the chemical formulas. If there is no coefficient, it is assumed to be 1. Explain to 
students that in this chapter they will use the coefficients from balanced equations to 
calculate the quantities of reactants or products in chemical reactions. 



Strategies to Explore 

• Facilitate a discussion with students about the similarities between a balanced chemical 
equation and a recipe. Students can think of balanced chemical equations as the recipes 
that chemists follow to produce products from reactants. 



Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 



Strategies to Extend and Evaluate 

• Read each statement in the lesson summary. Have students indicate whether or not 
they understand each statement by using thumbs up or thumbs down to show "Yes" 
or "No". Whenever a student uses a thumbs down to show "No", use this as an 
opportunity to review this concept with the class. DI (ELL) 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the lesson 17.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



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17.3 Lesson 17.2 ~"0303Mass-Mass Calculations 
Key Concepts 

In this lesson, students learn to calculate mass relationships in balanced chemical reactions. 



Lesson Objectives 

• The student will define stoichiometry. 

• Given the mass of one reactant or product, the student will calculate the mass of any 
other reactant or product. 

• The student will use the factor-label method in mass-mass calculations. 



Lesson Vocabulary 

• stoichiometry :The calculation of quantitative relationships of the reactants and 
products in a balanced chemical reaction. Sometimes it is called reaction stoichiometry 
to distinguish it form composition stoichiometry. 



Strategies to Engage 

• Explain to students that in the last lesson they explored mole relationships in balanced 
equations. In this lesson they will explore mass relationships in balanced equations. 
Have students read the introduction, lesson vocabulary and lesson objectives, then 
facilitate a discussion with students about what they think will be some similarities 
and differences between these two concepts. 



Strategies to Explore 

• Point out to students the importance of writing the correct units throughout the prob- 
lem, and that in the end, all of the units must cancel except for the desired unit. This 
will prevent students from bypassing the mole ratio and attempting to convert the 
mass of the given substance directly to the mass of the desired substance. 



• Divide students into groups of three or four to work on problems in this lesson. Assign 
one student in each group to serve as a reminder to the rest of the group members to 
include the proper units throughout the problems. 

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Strategies to Extend and Evaluate 

Lesson Worksheets 

Copy and distribute the Stoichiometry worksheet in the Supplemental Workbook. Ask stu- 
dents to complete the worksheets alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 17.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



17.4 Lesson 17.3 Limiting Reactant 
Key Concepts 

In this lesson, students learn to identify and calculated limiting and excess reactants in 
chemical reactions. 



Lesson Objectives 

• Identify the limiting reactant in a chemical reaction. 

• Identify excess reactants in chemical reactions. 

• Calculate the limiting reactant using the mole-mole ratios. 

• Calculate the products using the limiting reactant and the mass-mass ratios. 



Lesson Vocabulary 

• Limiting reactant: The reactant that is completely consumed when a reaction is run 
to completion. 



Excess reactant: The reactant or reactants that are left over when all of the limiting 
reactant has been consumed. 



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Strategies to Engage 

• Place five plates, four forks, four knives, and three spoons on a table in the classroom. 
Ask students how many place settings they can make from the given materials. Ex- 
plain to students that because there are only three spoons, they can make only three 
place settings. Have students read the lesson introduction and compare the concept of 
limiting, and excess, reagents to the demonstration. 



Have students give examples of limiting reagents in everyday life such as making sand- 
wiches. 



Strategies to Explore 

• Students often have trouble recognizing limiting reagent problems. Explain to students 
that any time they are given the amount of more than one reactant, they must first 
determine which reactant is the limiting reagent. 



Have students create a Venn diagram comparing and contrasting limiting and excess 
reagents. 



Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 



Strategies to Extend and Evaluate 

Lesson Worksheets 

Copy and distribute the Limiting Reactant Worksheet in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the lesson 17.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

www.ckl2.org 202 



17.5 Lesson 17.4~"0303 Percent Yield 
Key Concepts 

In this lesson, students learn to calculate theoretical, actual, and percent yield of a chemical 
reaction. 



Lesson Objectives 

• Define theoretical and actual yield. 

• Explain the difference between theoretical and actual yield. 

• Calculate percent yield (reaction efficiency). 

Lesson Vocabulary 

theoretical yield The amount obtained when all of the limiting reactant has reacted in 
the balanced chemical equation. 



actual yield The actual amount that is obtained from the experiment, and is always less 
than the theoretical yield. 



percent yield % yield = ^S^ X 100 

yield efficiency The percent yield of the reaction compared to the optimal yield. 

Strategies to Engage 

• Point out to students that if a chemical reaction occurs, in theory you can calculate 
how much of the product is created. However, in the real world, often not all the 
possible products are produced in a chemical reaction. Tell students that in this lesson 
they will explore reactions in which the product from a chemical reaction is less than 
was expected based on the balanced chemical equation. 



Strategies to Explore 

• Have students create a Venn diagram comparing and contrasting theoretical and actual 
yields. 



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• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• On the board or chart paper, have students write a class summary of this lesson. Have 
one student come up with the first sentence and have students contribute sentences 
until the entire lesson has been summarized. 

Lesson Worksheets 

Copy and distribute the Percent Yield Worksheet in the Supplemental Workbook. Ask 
students to complete the worksheets alone or in pairs as a review of lesson content. 

Review Questions 

Have students answer the lesson 17.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



17.6 Lesson 17.5~"0303 Energy Calculations 
Key Concepts 

In this lesson, students explore energy changes in chemical processes. 

Lesson Objectives 

• Define endothermic and exothermic reactions in terms of energy and AH. 

• Distinguish between endothermic and exothermic chemical changes. 

• Write AH reactions for a given number of moles of reactants or products. 

Lesson Vocabulary 

law of conservation of energy The energy of the universe is constant and is therefore 
conserved. 

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potential energy Energy of position. 

kinetic energy Energy of motion. 

endothermic Energy is absorbed in the reaction, AH is positive or AH > 0. 

exothermic Energy is released in the reaction, AH is negative or AH < 0. 

heat of reaction, AH rxn The change in energy from the products to the reactants (AH reaction 

■" products ■" reactants ) ■ 

enthalpy A measure of the energy content of a system. 

AHf Heat of Formation; the energy change when 1 mole of a substance is produced from 
its elements in their standard states. 

AH com Heat of combustion; the energy change that occurs when 1 mole of a fuel is reacted 
with oxygen. 

Strategies to Engage 

• Place 20ml of water into each of two 50ml beakers. Measure and record the temperature 
of the water in each beaker. Into one beaker, add 2g of baking soda. Into the other 
beaker, add 2g of sodium hydroxide. Measure and record the temperature of each 
solution. The temperature of the sodium hydroxide solution should have increased, 
while the temperature of the baking soda solution should have decreased. Explain 
to students that when chemical processes take place, they are often accompanied by 
energy changes. Tell students that in this lesson they will explore these energy changes 
that occur in chemical processes. 

Strategies to Explore 

• It is important to define the system and surroundings. Point out to students that the 
reaction mixture constitutes the system. The surroundings are everything else. 

Strategies to Extend and Evaluate 

• Have students work in pairs to create a concept map relating the concepts explored 
in this lesson. Encourage students to include the drawings as well as the text in their 
concept map. 

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Have students bring in examples of endothermic and exothermic processes that occur 
in everyday. Students should be prepared to discuss their findings with the rest of the 
class. 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the lesson 17.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 17 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 17 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



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Chapter 18 

TE The Kinetic Molecular Theory 



18.1 Unit 6 ~"0303 Kinetic Molecular Explanation and 
the States of Matter 

Outline 

This unit, Kinetic Molecular Explanation and the States of Matter, includes the following 
chapters that explore the properties of the states of matter in terms of the Kinetic Molecular 
Theory. 

. Chapter 18 ~ "0303 The Kinetic Molecular Theory 
. Chapter 19 ~ "0303 The Liquid State 
. Chapter 20 ~ "0303 The Solid State 

Overview 

The Kinetic Molecular Theory 

This chapter describes the molecular structure and properties of gases, and develops both 
the combined gas law and the universal gas law. The stoichiometry of reactions involving 
gases is also covered. 

The Liquid State 

This chapter covers the causes of the liquid condensed phase and the properties of liquids. 
It includes a section on the energy involved in liquid to gas phase changes and a section 
introducing colligative properties. 

The Solid State 

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The various intermolecular forces of attraction are discussed in this chapter and the proper- 
ties of solids produced by each type of intermolecular force of attraction are pointed out. 



18.2 Chapter 18~"0303The Kinetic Molecular Theory 
Key Concepts 

The chapter The Kinetic Molecular Theory consists of seven lessons that describe the molec- 
ular structure and properties of gases, and develops both the combined gas law and the 
universal gas law. The stoichiometry of reactions involving gases is also covered. 

Lesson 18.1 ~"0303The Three States of Matter 

Lesson 18.2 ~"0303Gases 

Lesson 18.3 ~"0303Gases and Pressure 

Lesson 18.4~"0303Gas Laws 

Lesson 18.5 ~"0303Universal Gas Law 

Lesson 18.6 ~"0303Molar Volume 

Lesson 18.7~"0303Stoichiometry Involving Gases 

Overview 

In these lessons, student will explore: 

The differences among the three states of matter. 

The behavior and properties of gases. 

The definition and measurement of gas pressure. 

Mathematical relationships among gas pressure, temperature, and volume. 

Calculations involving the universal gas law. 

The volume of a mole of gas at STP. 

Stoichiometric relationships involving reacting gas volumes. 

Science Background Information 
Elastic versus Inelastic Collisions 

The momentum, (rho), of an object is defined as the mass of the object multiplied by its 
velocity, mv. The velocity of an object and the momentum of the object are vectors. That 
is a statement of either the velocity or the momentum of an object includes the direction 
that the object is traveling. The direction is an integral part of the measurement. If we 



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assign the direction north to be positive direction, then a 5.0 kg object traveling north at 7.0 
meters/second will have a momentum of +35 kg ■ m/s. In this same system, a 5.0 kg object 
traveling south at 7.0 m/s will have a momentum of -35 kg • m/s. During collisions between 
objects, momentum is always conserved. In this system (consisting of these two objects), 
the total momentum of the system is kg • m/s because (+35 kg • m/s) + (-35 kg • m/s) = 
0. If these two objects collide and bounce directly backwards with velocity exactly opposite 
to their original velocities, the object that had a momentum of +35 kg • m/s will now have 
a momentum of -35 kg ■ m/s and the object whose original momentum was -35 kg • m/s 
will now have a momentum of +35 kg-m/s. The total momentum of the system is still 
kg • m/s and momentum has been conserved (as it always is). If these two objects collide 
and stick together (like two balls of Play Doh), both velocities become zero. In such a case, 
the momentum of each object is zero, the total momentum of the system is zero, and once 
again, momentum is conserved. 

The kinetic energy, KE, of an object is defined as one-half the mass of an object multiplied 
by its velocity squared, KE = Vi mv 2 . The kinetic energy of an object is NOT a vector. 
An 5.0 kg object traveling north at 7.0 m/s will have a KE = x h (5.0 kg) (7.0 m/s) 2 = 120 
kg • m/s 2 = 120 Joules. In this same system, a 5.0 kg object traveling south at 7.0 m/s will 
also have a kinetic energy of 120 Joules . . . there is no direction associated with kinetic 
energy. Therefore, the total kinetic energy in this system is 240 Joules . . . the opposite 
directions of the ball's motions do not cause cancellation when dealing with kinetic energy. 
If these two objects collide and bounce directly backwards with velocities exactly opposite 
to their original velocities, each object will have the same kinetic energy it had before the 
collision and the total kinetic energy of the system will still be 240 Joules . . . kinetic 
energy has been conserved. If these two objects collide and stick together (like two balls of 
Play Doh), both velocities become zero. In such a case, the kinetic energy of each object 
is zero, the total kinetic energy of the system is zero, and kinetic energy is not conserved. 
Since energy, all forms considered, is conserved in all interactions except nuclear, the kinetic 
energy that was lost in the collision must be found in some other form, usually heat and 
sound. Make sure you understand that energy is conserved in non-nuclear interactions, but 
the form of the energy is not necessarily conserved. Specifically, KE is not conserved in the 
collision but energy in all forms is conserved. Mechanical energy may become electrical or 
electrical energy may become light, but when all forms of energy are added up, energy is 
conserved. 

Considering collisions of all sorts, collisions between automobiles, collisions between tennis 
balls and walls, collisions between billiard balls, momentum is always conserved and kinetic 
energy is almost never conserved. When automobiles collide, metal parts are bent, causing 
parts to rub against each other, and friction turns kinetic energy into heat and sound. Even 
a tennis ball bouncing on the ground slowly loses energy of motion as it bounces. When the 
tennis ball strikes the ground, it is deformed and this deformation stores energy in the ball 
and as the ball regains its shape, the ball bounces back up in the air and the stored energy 
again becomes energy of motion. But, in the process, the deformation of the ball causes 



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internal friction which is converted to heat and the ball will not bounce as high after each 
bounce. The tennis ball will bounce lower and lower until all the energy has been converted 
to heat. You probably cannot detect the temperature increase in a tennis ball but the same 
thing occurs when a hammer pounds on a nail and if you touch the nail after several strikes, 
you will feel the higher temperature. Only a few collisions in nature come close to conserving 
kinetic energy. The collisions between billiard balls or between polished steel balls come quite 
close to conserving kinetic energy. A popular demonstration of conservation of momentum 
and conservation of kinetic energy features several polished steel balls hung in a straight line 
in contact with each other. 



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Table 18.1: 



If one ball is pulled back 
and allowed to fall and strike 
the line of balls, exactly one 
ball will fly out the other 
side. The other balls, in- 
cluding the one which was 
dropped will remain motion- 
less. 

If two balls are pulled back 
and allowed to fall and strike 
the line of balls, exactly two 
balls will fly out the other 
side. The other balls, in- 
cluding the two that were 
dropped will remain motion- 
less. 

In the extreme case, if four 
balls are pulled back and al- 
lowed to fall, to strike the 
single motionless ball, four 
balls will fly out the other 
side, leaving one motionless 
ball. 

The reason this strange 
phenomena occurs is that 
both momentum and ki- 
netic energy are conserved 
in these collisions. Momen- 
tum would be conserved if 
one ball dropped at veloc- 
ity X and two balls flew out 
the other side with velocity 
Vi X but this would not con- 
serve kinetic energy. In or- 
der for kinetic energy to be 
conserved, the same number 
of balls must fly out with the 
same velocity as the balls 
that were dropped. 



CQOOO 




0000 ccc 




COO OCX 



211 



www.ckl2.org 



When kinetic energy is conserved in a collision, physicists refer to the collision as a perfectly 
elastic collision. Why do we offer all this physics information to a chemistry teacher? The 
answer is that collisions between ideal gas particles are perfectly elastic collisions, that is, 
kinetic energy is conserved in collisions between gas particles. That's why when gas particles 
are bouncing around inside a container and exerting pressure, they do not gradually lose 
kinetic energy resulting in a lower pressure (as they would do if they were tennis balls). 

There are cases, however, when gas particles do gain or lose kinetic energy without heat being 
added or removed from an external source. Consider a gas trapped in a closed cylinder fitted 
with a piston. 



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Table 18.2: (continued) 



Table 18.2: 



Consider the situation when 
the piston is held in posi- 
tion by hand. If the pres- 
sure inside the cylinder is 
greater than the external 
pressure, then releasing the 
piston will allow the gas in- 
sider the cylinder to push 
the piston higher. Moving 
the piston higher requires 
energy. Since the piston is 
being pushed higher by the 
gas inside the cylinder, the 
energy must come from the 
gas. The molecules of gas 
that strike the piston and 
push it upward are doing 
work (force x distance) and 
will lose some kinetic energy. 
Therefore, those molecules 
slow down. The average ki- 
netic energy of the molecules 
in the cylinder becomes less 
and therefore, the tempera- 
ture will be lower (temper- 
ature is proportional to the 
average kinetic energy of the 
molecules). Thus, the ex- 
pansion of the gas against 
a force (outside pressure, 
gravity, etc.) causes the gas 
to cool slightly. Conversely, 
if you push the piston down, 
thus compressing the gas, 
your hand is doing work 
on the molecules the pis- 
ton strikes. Those molecules 
will gain kinetic energy and 
so the average KE of the 
molecules increases. The 
wtWMpfc-Kffl^ of the gas will 
increase slightly. Thus, the 
compression of the gas raises 
its temperature slightly. 




214 



Table 18.2: (continued) 



Suppose you have two boxes, one containing a gas and one containing a vacuum, and you 
open a valve between the boxes so the gas can expand into the vacuum. In this case, the gas 
is not pushing against anything, so it is not doing work and there will be no temperature 
change. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of The Kinetic 
Molecular Theory. 

60 Minute Class Periods per Lesson 

Table 18.3: 



Lesson 



Number of Class Periods 



18.1 The Three States of Matter 

18.2 Gases 

18.3 Gases and Pressure 

18.4 Gas Laws 

18.5 Universal Gas Law 

18.6 Molar Volume 

18.7 Stoichiometry Involving Gases 



0.5 

0.5 
1.0 
2.0 
2.0 
0.5 
1.5 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for The Kinetic Molecular Theory. 

The Kinetic Molecular Theory Materials List 

Table 18.4: 



Lesson 



Strategy or Activity 



Materials Needed 



18.1 
18.2 



Engagement Activity 

215 



Bottle of perfume 

www.ckl2.ore 



Table 18.4: (continued) 



Lesson Strategy or Activity Materials Needed 

18.3 Engagement Activity Balloon 

18.4 Engagement Activity Aluminum soda can, hot 

plate, tongs, bucket . 
18.5 

18.6 Engagement Activity Poster board, tape. 
18.7 



Multimedia Resources 

You may find these additional web based resources helpful when teaching The Kinetic Molec- 
ular Theory: 

• Lesson on temperature and absolute zero: http : //www. Colorado . edu/UCB/AcademicAf fairs/ 
ArtsSciences/physics/PhysicsInitiative/Physics2000/bec/temperature .html 

• Particle motion computer simulation: http://intro.chem.okstate.edu/1314F00/ 
Laboratory/GLP . htm 

• Animated Boyle's Law: http: //www.grc .nasa.gov/WWW/K-12/airplane/aboyle .html 

Possible Misconceptions 

Identify: Students may think that air does not have mass and does not take up space. 

Clarify: Air is a mixture of gases. It contains 78% nitrogen, 21% oxygen, less than 1% argon, 
with trace amounts of other gases. 

Promote Understanding: Tell students to wave their hands in front of their faces. Explain 
to student that although they cannot see the air, they could feel its effects. Measure and 
record the mass of a Ziploc bag. Fill the bag with air, and measure and record the mass 
again. Students will notice that air does have mass. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in The Kinetic Molecular Theory 
www.ckl2.org 216 



Table 18.5: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



18.1 

18.2 4a, 4f, 4g, 7a 

18.3 4a 

18.4 4c, 4d 

18.5 4c, 4h 

18.6 4b, 4i 
18.7 



18.3 Lesson 18.1 ~"0303The Three States of Matter 
Key Concepts 

In this lesson, students will explore the differences among the three states of matter in terms 
of both properties and structure. 



Lesson Objectives 

• The students will describe molecular arrangment differences among solids, liquids, and 
gases. 

• The students will describe the basic characteristic differences among solids, liquids, 
and gases. 



Lesson Vocabulary 

phase Any of the forms or states, solid, liquid, gas, or plasma, in which matter can exist, 
depending on temperature and pressure. 



kinetic The term "kinetic" refers to the motion of material bodies and the forces associated 
with them. 



molecule In the kinetic theory of gases, any gaseous particle regardless of composition 

21 7 www.ckl2.org 



Strategies to Engage 

• Have each student draw a model of the particle arrangement in solids, liquids, and 
gases. Use this as an opportunity to clear up any misconceptions students may have 
about three states of matter. 

Strategies to Explore 

• Have student play a game of charades. Groups of students will act out one of the 
assumptions of the kinetic molecular theory, while the rest of the class tries to guess 
which assumption they are demonstrating. 

• This lesson includes description of the characteristics of solids, liquids, and gases. 
Before reading, prepare less proficient readers by having students write the following 
on the top of separate sheets of notebook paper: 

Characteristics of Solids 

Characteristics of Liquids 
Characteristics of Gases 

As they read each section have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

Strategies to Extend and Evaluate 

• Have students write a letter convincing the reader of the kinetic molecular theory. 
Instruct students to include real life examples in their letters. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 18.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



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18.4 Lesson 18.2 ~"0303Gases 
Key Concepts 

In this lesson, students will explore the behavior and properties of gases. 

Lesson Objectives 

• The students will describe the relationship between molecular motion and Kelvin tem- 
perature. 

• The students will describe random motion of gas molecules and explain how their 
collisions with surfaces cause pressure on the surface. 

• The students will state that zero kinetic energy of molecules corresponds to K and 
that there is no lower temperature. 

Lesson Vocabulary 

kinetic energy Kinetic energy is the energy a body possesses due to it motion, KE = 
1/2 mv 2 . 

Kelvin temperature The absolute temperature scale where K is the theoretical absence 
of all thermal energy (no molecular motion). 

Strategies to Engage 

• Open a bottle of perfume in the front of the room. Ask student to raise their hands 
when they are able to smell the scent. Ask a volunteer to explain, in terms of the 
kinetic molecular theory, why they are able to smell the scent. 

Strategies to Explore 

• Tell students to find the average low and high temperature of the previous day. Then 
have them convert the temperature in Fahrenheit into degrees Celsius and Kelvin. 
Students can draw three thermometers showing the equivalent temperatures on the 
three scales. 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI (LPR) 

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Strategies to Extend and Evaluate 

• Read each statement in the lesson summary. Have students indicate whether or not 
they understand each statement by using thumbs up or thumbs down to show "Yes" 
or "No". Whenever a student uses a thumbs down to show "No", use this as an 
opportunity to review this concept with the class. DI (ELL) 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 18.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

18.5 Lesson 18.3~"0303Gases and Pressure 



Key Concepts 



In this lesson, students will learn the definition of pressure and methods of measuring gas 
pressure. 



Lesson Objectives 

• The student will define pressure. 

• The student will convert requested pressure units. 

• The student will read barometers and both open-end and closed-end manometers. 

• The student will apply the gas laws to relationships between the pressure, temperature, 
and volume of a gas. 

• The student will state standard conditions for gases. 



Lesson Vocabulary 

barometer A barometer is an instrument used to measure atmospheric pressure. 
www.ckl2.org 220 



manometer A manometer is a liquid column pressure measuring device. 



Strategies to Engage 

• Blow up a balloon. Ask students to list factors that influence the pressure of the air 
inside of the balloon. Students should respond that gas pressure is influenced by: the 
number of moles of gas in the container; its volume; and its temperature. Explain to 
students that in this chapter they will explore the relationships among these factors. 



Strategies to Explore 

• Ask students to look at Figure 7 and Figure 8. Have them write a paragraph to describe 
what is happening in each illustration. 



Have students create a Venn diagram comparing and contrasting barometers and 
manometers. 



Explain to students that the force exerted on the floor when you stand on one foot is 
the same amount of force you exert on the floor when you stand on two feet. However, 
when you stand on one foot, the pressure or force per unit area is more. 



Strategies to Extend and Evaluate 

• Encourage interested students to research the science of scuba diving. Students should 
be prepared to share their findings with the rest of the class. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have the students answers the Lesson 18.3 Review Questions that are listed at the end of 
the lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



221 www.ckl2.org 



18.6 Lesson 18.4~"0303Gas Laws 
Key Concepts 

In this lesson, the students will study mathematical relationships among gas pressure, tem- 
perature, and volume. 

Lesson Objectives 

• The students will state Boyle's Law, Charles' Law, and Gay-Lussac's Law. 

• The students will solve problems using Boyle's Law, Charles' Law, and Gay-Lussac's 
Law. 

• The students will state the combined gas law. 

• Using the combined gas law, and given any five of the six variables, the students will 
solve for the sixth variable. 

Lesson Vocabulary 

barometer An instrument used to measure atmospheric pressure. 

dalton The unified atomic mass unit, or Dalton, is a unit of mass used to express atomic 
and molecular masses. It is the approximate mass of a hydrogen atom, a proton, or 
a neutron. The precise definition is that it is one-twelfth of the mass of an unbound 
carbon-12 atom at rest. 

manometer A liquid column pressure measuring device. 

Strategies to Engage 

• Place about 5ml of water into an aluminum soda can and place it on a hot plate until 
you see steam rising from the can. Use a pair of tongs to grab the can and quickly 
invert the can into a bucket of cold water. Explain to students that the cold water 
quickly cooled the gas inside of the can. This pressure inside of the can decreased, and 
the atmospheric pressure was able to crush the can. 

Strategies to Explore 

• The internet is filled with simple demonstrations of the gas laws explored in this lesson. 
Ask groups of students to find, perform, and explain some of these demonstrations for 
their classmates. 

www.ckl2.org 222 



Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 



Divide students into groups of three or four to work on problems in this lesson. Assign 
one student in each group to serve as a reminder to the rest of the group members to 
use consistent units throughout the problems. Assign another student to serve as a 
reminder to convert temperatures from °C to K. 



Strategies to Extend and Evaluate 

Lesson Worksheets 

Duplicate and distribute the worksheet "Kinetic Molecular Theory and Gas Laws" and ask 
students to complete it either individually or in small groups. 



Review Questions 

Have students answer the Lesson 18.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



18.7 Lesson 18.5 ~"0303Universal Gas Law 
Key Concepts 

In this lesson, students learn and practice calculations involving the universal gas law. 

Lesson Objectives 

• The students will solve problems using the Universal Gas Law, PV = nRT. 

• The students will state Avogadro's Law of equal molecules in equal volumes under the 
same conditions of temperature and pressure. 

• The students will calculate molar mass from mm = S py r , given mass, temperature, 
pressure, and volume. 

223 www.ckl2.org 



Lesson Vocabulary 

universal gas law constant, R R is a constant equal ^ where the pressure, volume, 
moles, and temperature of the gas are P, V, n, and T, respectively. The value and 
units of R depend on the units of P and V. Commonly used values of R include; 

82.055 mL 3 atm K~ l mol" 1 , 0.082055 L atm K' 1 mol" 1 , 8.314 JK _1 mol" 1 , 8.314 Pa m 3 K _1 mol" 1 . 

Strategies to Engage 

• Facilitate a discussion with students about the relationships among pressure, temper- 
ature, and volume of a gas explored so far in this chapter. 

Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

• Divide students into groups of three or four to work on problems in this lesson. Assign 
one student in each group to serve as a reminder to the rest of the group members to 
use consistent units throughout the problems. Assign another student to serve as a 
reminder to convert temperatures from °C to K. 

Strategies to Extend and Evaluate 

• Encourage interested students to research the science of car engines and how they 
relate to the gas laws. Students should be prepared to share their findings with the 
rest of the class. 

• Have students create study cards of the equations explored in this chapter. 

Lesson Worksheets 

Review Questions 

Have students answer the Lesson 18.5 Review Questions that are listed at the end of the 
lesson in the FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

www.ckl2.org 224 



18.8 Lesson 18.6~"0303Molar Volume 
Key Concepts 

In this lesson, students learn the volume of one mole of any gas at Standard Temperature 
and Pressure (STP) and applications of that information. 

Lesson Objectives 

• The students will apply the relationship 1.00 mole of any gas at standard conditions 
will occupy 22.4 L. 

• The students will convert gas volume at STP to moles and to molecules and vice versa. 

• The students will apply Dalton's Law of Partial Pressures to describe the composition 
of a mixture of gases. 

Lesson Vocabulary 

diffusion The movement of particles from areas of higher concentration to areas of lower 
concentration of that particle. 

partial pressure The pressure that one component of a mixture of gases would exert if it 
were alone in a container. 

molar volume The volume occupied by one mole of a substance in the form of a solid, 
liquid, or gas. 

Strategies to Engage 
Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• Ask groups of students to use poster board and tape to build a cube that will hold 
exactly 1.00 mol of a gas at STP. Award a prize to the first group who is able to build 
the cube with the correct dimensions and explain the calculations involved. 

225 www.ckl2.org 



Lesson Worksheets 

Review Questions 

Have students answer the Lesson 18.6 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

18.9 Lesson 18.7~"0303Stoichiometry Involving Gases 



Key Concepts 

In this lesson, students explore stoichiometric relationships involving gas volume. 



Lesson Objectives 

• The students will solve stoichiometry problems involving converting gas volume at STP 
to moles and vice versa. 

• The students will solve stoichiometry problems involving gas volume to gas volume 
under any conditions of temperature and pressure. 



Strategies to Engage 

• Explain to students that in the last lesson they explored molar volume of gases at STP. 
In this lesson they will solve stoichiometry problems involving volume relationships in 
balanced equations. Have students read the introduction, lesson vocabulary and lesson 
objectives, then facilitate a discussion with students about how they think they will 
perform these calculations. 



Strategies to Explore 

• Point out to students the importance of writing the correct units throughout the prob- 
lem, and that in the end, all of the units must cancel except for the desired unit. This 
will prevent students from bypassing the mole ratio and attempting to convert the 
volume of the given gas directly to the volume of the desired gas. 



www.ckl2.org 226 



Strategies to Extend and Evaluate 

Lesson Worksheets 

Review Questions 

Have students answer the Lesson 18.7 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 18 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 18 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



227 www.ckl2.org 



www.ckl2.org 228 



Chapter 19 

TE The Liquid State 



19.1 Chapter 19~"0303The Liquid State 
Outline 

The chapter The Liquid State consists of five lessons that cover the causes of the liquid 
condensed phase and the properties of liquids. It includes a section on the energy involved 
in liquid to gas phase changes and a section introducing colligative properties. 



Lesson 19.1~"0303 The Properties of Liquids 
Lesson 19.2~"0303 Forces of Attraction 
Lesson 19.3~"0303 Vapor Pressure 
Lesson 19.4 ""0303 Boiling Point 
Lesson 19.5~"0303 Heat of Vaporization 



Overview 

In these lessons, students will explore: 



The behavior of liquids. 

Intermolecular forces of attraction. 

Vaporization, condensation, and vapor pressure. 

The relationship between vapor pressure and boiling point. 

The energy changes involved in cooling and heating. 



229 www.ckl2.org 



Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Refrigeration 

Vaporization is the phase change from liquid to gas at the boiling point of the liquid. When 
this phase change occurs below the boiling point of the liquid, it is called evaporation. Liquids 
undergo evaporation because while the average temperature of its molecules is less than the 
boiling point, some of the molecules have temperatures above the boiling point. These hot 
molecules are the ones that leave the liquid phase and enter the gaseous phase. During both 
vaporization and evaporation, the amount of liquid that leaves the liquid phase and enters 
the gaseous phase absorb the heat of vaporization. When the ambient temperature of a 
gaseous substance is above the boiling point of the liquid of that substance, scientists called 
the substance a gas. But when the ambient temperature of a gaseous substance is below the 
boiling point of the liquid of that substance, they call it a vapor. Hence, gaseous water at 
an ambient temperature of 120°C is water gas and gaseous water at an ambient temperature 
of 70°C is water vapor. 

The process of evaporation has long been used to cool food and drink. 

Canteens are frequently covered in fabric or carried in a fabric holder. The canteen user 
wets the fabric when filling the canteen so that as the water evaporates from the fabric, it 
absorbs the heat of vaporization from the canteen and cools the canteen, making the water 
more pleasant to drink. 

Some people put butter on the dinner table with the dish holding the butter sitting inside 
another dish half-filled with water. As the water in the outside dish evaporates, it absorbs 
the heat of vaporization, cools the butter dish and keeps the butter from melting. 

Before the days of the portable ice chest, people who took bottled or canned drinks on a 
picnic would often keep the drinks in a fabric bag that they would soak with water on arrival 
at the picnic spot. The evaporation of the water would keep the drinks much cooler than if 
they were sitting out on a table. 

The function of refrigerators and air conditioners also involve the heat of vaporization of 
liquids. 

Many gaseous substances can be compressed until they become liquids. That is, the molecules 
are pushed together forcefully until they touch and the gas becomes a liquid. In this process, 
the gas also gives up the heat of vaporization as it becomes a liquid. By compressing the 
coolant to a liquid outside the refrigerator, the phase change gives up the heat of vaporiza- 
tion outside the refrigerator. The liquid coolant is then pumped through a tube inside the 
refrigerator where it is allowed to vaporize back to gas, thus absorbing the heat of vapor- 
ization inside the refrigerator. Then the gas is pumped outside the refrigerator and again 
compressed to liquid, giving up the heat of vaporization. In this manner, heat is absorbed 

www.ckl2.org 230 



from inside the refrigerator and given off outside the refrigerator. The inside gets colder 
and the outside gets warmer. This is why you can feel heat coming from the back or from 
underneath a refrigerator. This is also why the compressor for an air conditioner must be 
outside the house. It wouldn't do much good to absorb the heat and release the heat both 
inside the house. So much for the idea of cooling the house by leaving the refrigerator door 
open. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of The Liquid State. 
60 Minute Class Periods per Lesson 

Table 19.1: 



Lesson 



Number of Class Periods 



19.1 The Properties of Liquids 

19.2 Forces of Attraction 

19.3 Vapor Pressure 

19.4 Boiling Point 

19.5 Heat of Vaporization 



0.5 
1.0 
0.5 
0.5 
1.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for The Liquid State. 

Chapter 19 Materials List 

Table 19.2: 



Lesson 



Strategy or Activity 



Materials Needed 



19.1 
19.2 

19.3 
19.4 
19.5 



Exploration Activity 
Exploration Activity 

231 



Pennies, dropper pipets, al- 
cohol, distilled water 



Ice, beakers, thermometer, 
hot plate, ring stand assem- 

bly 

www.ckl2.ore 



Table 19.2: (continued) 



Lesson Strategy or Activity Materials Needed 

Multimedia Resources 

You may find these additional web based resources helpful when teaching The Liquid State: 

• Fill-in-the-blank worksheet generator: http : //www . theteacherscorner . net/printable-workshee 
make-your-own/f ill-in-the-blank/ 

Possible Misconceptions 

Identify: Students may think that boiling and vaporization have the same meaning. Also, 
students may not understand the difference between evaporation and boiling. 

Clarify: Vaporization is the transition of a liquid to a gas. Vaporization can take place in 
two ways: evaporation and boiling. Evaporation occurs when some particles within a liquid 
have more energy than others, and are able to escape from the surface of the liquid as gas or 
vapor. Evaporation takes place below the boiling point of the liquid. Boiling happens when 
the vapor pressure of the liquid is equal to atmospheric pressure. 

Promote Understanding: Have students construct a simple concept map illustrating the 
relationships among boiling, vaporization, and evaporation. The concept map should show 
that evaporation and boiling are types of vaporization. 

Identify: Students may think that the temperature of a liquid increases as it boils. 

Clarify: The temperature of a boiling liquid never goes above its boiling point no matter 
how much heat is applied to it. 

Promote Understanding: Have students measure and record the temperature of a sample of 
water every at 30 second interval as it boils. Ask students to construct a graph of time vs. 
temperature. Students should see that the temperature does not change. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in The Liquid State 

www.ckl2.org 232 



Table 19.3: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



Lesson 19.1 






Lesson 19.2 


2d, 


2h 


Lesson 19.3 


7c 




Lesson 19.4 


7c 




Lesson 19.5 


7c, 


7cl 



19.2 Lesson 19.1 ~"0303The Properties of Liquids 
Key Concepts 

In this lesson, students explore the behavior and properties of liquids. 

Lesson Objectives 

• The student will explain the basic behavior and characteristics of liquids using the 
molecule arrangement present in liquids. 

Lesson Vocabulary 

incompressible The terms compressibility and incompressibility describe the ability of 
molecules in a fluid to be compacted (made more dense). 

Strategies to Engage 

• Ask students what they already know about liquids. Use this opportunity to gauge 
student understanding of the properties of liquids and to clear up any misconceptions. 

Strategies to Explore 

This lesson includes a description of the basic behavior and properties of liquids. Before 
reading, prepare less proficient readers by having students write the following on the top of 
separate sheets of notebook paper: 

• Liquids Maintain Their Volume But Take the Shape of Their Container 

233 www.ckl2.org 



• Liquids Have Greater Densities Than Gases 

• Liquids are Almost Incompressible 

• Liquids Diffuse More Slowly Than Gases 

As students read each section, have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

Strategies to Extend and Evaluate 

• Encourage interested students to research fluids and write a paragraph explaining why 
liquids and gases are classified as fluids. 

• Have students work in pairs or teams to write a poem about liquids. Their poems 
should explain what liquids are, some of their properties, and how they differ from 
gases. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 19.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

19.3 Lesson 19.2 ~"0303Forces of Attraction 
Key Concepts 

In this lesson, students explore intermolecular forces of attraction. 

Lesson Objectives 

• The student will identify liquids whose intermolecular forces of attraction are due to 
London dispersion forces, polar attractions, and hydrogen bonding. 

www.ckl2.org 234 



• The student will describe some of the unique properties of water that are due to 
hydrogen bonding. 

• The student will select from comparative compounds, the ones most likely to form 
hydrogen bonding. 

• The student will select from comparative compounds whose intermolecular forces are 
London dispersion forces, the one most likely to have the strongest intermolecular 
forces. 

Lesson Vocabulary 

hydrogen bond The exceptionally strong polar attraction between a hydrogen atom in 
one molecule and a highly electronegative atom (N,0,F) in another molecule. 

London dispersion forces Electrostatic attractions of molecule or atoms for nearby atoms 
or molecules caused by the temporary unsymmetrical distribution of electrons in elec- 
tron clouds. 

Strategies to Engage 

• Prior to beginning this lesson, have students look up examples of terms that begin with 
the prefixes "intra" and "inter". Ask them to write down the meanings of the words. 
Facilitate a discussion with students about how these prefixes relate to molecules. 

Strategies to Explore 

• Have students create a Venn diagram comparing and contrasting intermolecular forces 
and chemical bonds. 

• Have students place three drops of distilled water and three drops of alcohol on two 
separate pennies. Ask students write a paragraph explaining their observations in 
terms of intermolecular forces of attraction in each liquid. 

• Ask students to look at Figure 8 and write a paragraph describing what is happening 
in the illustration. 

Strategies to Extend and Evaluate 

• Encourage interested groups of students to create Keynote or PowerPoint slideshow 
presentations explaining the intermolecular forces of attraction explored in this lesson 
to share with the rest of the class. Students should include illustrations and examples 
of each type of intermolecular force. 



235 www.ckl2.org 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 19.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

19.4 Lesson 19.3~"0303 apor Pressure 
Key Concepts 

In this lesson, students will learn about vaporization, condensation, and vapor pressure. 

Lesson Objectives 

• The students will describe the processes of evaporation and condensation. 

• The students state the factors that control the rates of evaporation and condensation. 

• The students will describe vapor pressure equilibrium. 

Lesson Vocabulary 

condensation The process whereby a gas or vapor is changed to a liquid. 

equilibrium vapor pressure The pressure that is exerted, at a given temperature, by 
the vapor of a solid or liquid in equilibrium with the vapor. 

evaporation The escape of molecules from a liquid into the gaseous state at a temperature 
below the boiling point. 

heat of condensation The quantity of heat released when a unit mass of a vapor, con- 
denses to liquid at constant temperature. 

heat of vaporization The quantity of heat required to vaporize a unit mass of liquid at 
constant temperature. 

www.ckl2.org 236 



vapor The gaseous phase of a substance that exists even though the temperature is below 
the boiling point of the substance. 



Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 



Strategies to Explore 

• Have students create a graph of the vapor pressure of water at various temperatures 
from the table shown in this lesson. Ask them to correctly identify the boiling point 
of water on the graph, and then write a paragraph explaining the graph in their own 
words. 



Ask students to look at Figure 15 and write a paragraph to describe what is happening 
in the illustration. 



Strategies to Extend and Evaluate 

• Have students create a concept map of vocabulary terms. Tell students to relate 
vocabulary terms to the concepts explored in this lesson, and to correctly illustrate the 
relationships between the terms and the concepts. 



Have students use grid paper to make a crossword puzzle using the vocabulary terms. 
Ask students to exchange papers with a classmate and solve each other's puzzles. 



Challenge students to write an illustrated children's story that includes examples of 
condensation and vaporization they encounter in an average day (water puddles evap- 
orating, fog forming on mirrors). 



Have each student record the four sentences in this section that most clearly represent 
the main ideas. Read key sentences in the text and have students raise their hands 
if they have recorded that sentence. Facilitate a discussion in which students defend 
their selections. 



23 7 www.ckl2.org 



Lesson Worksheets 

Review Questions 

Have students answer the Lesson 19.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

19.5 Lesson 19.4~"0303Boiling Point 
Key Concepts 

In this lesson, students will learn the relationship between vapor pressure and boiling point. 

Lesson Objectives 

• The students will state the relationship between boiling point, vapor pressure, and 
ambient pressure. 

• Given a vapor pressure table for water, and the ambient pressure, the students will 
determine the boiling point of water for specified conditions. 

Lesson Vocabulary 

boiling point The temperature at which the vapor pressure of a liquid equals the sur- 
rounding pressure. 



normal boiling point The temperature at which the vapor pressure of a liquid equals 
1.00 atmosphere. 



Strategies to Engage 

• Ask students to look at Figure 17. Facilitate a discussion with students about why 
they think the water is able to boil at 20 °C. Explain to students that in this lesson 
they will explore how and why boiling point changes with changes in pressure. 

www.ckl2.org 238 



Strategies to Explore 

• Have students create a Venn diagram comparing and contrasting boiling point with 
normal boiling point. 



Strategies to Extend and Evaluate 

• Have each student write five fill-in-the-blank statements with the blank at the end of 
the sentence about key concepts explored in this lesson. Have students exchange papers 
with another student who will try to complete the sentence by filling in the blank. Have 
them hand the papers back to the original student who will assign a grade. Encourage 
students to discuss any incorrect answers. Students can also generate fill-in-the-blank 
worksheets at: 



http : //www . theteacherscorner . net /print able- worksheet s/make-your- own/fill- in- the-blank/ 

Lesson Worksheets 

Review Questions 

Have students answer the Lesson 19.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

19.6 Lesson 19.5 ~"0303Heat of Vaporization 
Key Concepts 

In this lesson, students will learn to calculate the energy changes during phase changes. 



Lesson Objectives 

• The student will calculate energy changes during phase changes. 

• The student will explain the slopes of various parts of heating and cooling curves. 

239 www.ckl2.org 



Lesson Vocabulary 

heat of condensation The quantity of heat released when a unit mass of a vapor con- 
denses to liquid at constant temperature. 

heat of vaporization The quantity of heat required to vaporize a unit mass of liquid at 
constant temperature. 

Strategies to Engage 
Strategies to Explore 

• Have groups of students create a heating curve for water. Ask students to write a 
materials list, procedure, and data table and approve them before proceeding. Stu- 
dents should then write a paragraph that includes the vocabulary terms explaining the 
heating curve. 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

• Use Figure 18 to explain as many concepts as possible. Relate concepts such as heat 
of vaporization, heat of condensation, and specific heat to Figure 18. DI (ELL) 

Strategies to Extend and Evaluate 

Lesson Worksheets 

Review Questions 

Have students answer the Lesson 19.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 19 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 
www.ckl2.org 240 



Chapter 19 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



241 www.ckl2.org 



www.ckl2.org 242 



Chapter 20 



TE The Solid State-HSC 



20.1 Chapter 20~"0303The Solid State 
Outline 

The chapter The Solid State consists of four lessons that discuss the various intermolecular 
forces of attraction. Also discussed are the properties of solids produced by each type of 
intermolecular force of attraction. 



• Lesson 20.1 ~"0303 The Molecular Arrangement in Solids Controls Solid 
Characteristics 

. Lesson 20.2 ~ "0303 Melting 

. Lesson 20.3 ""0303 Types of Forces of Attraction for Solids 

• Lesson 20.4~"0303 Phase Diagrams 



Overview 

In these lessons, students will explore: 



The characteristics of solids. 

Energy changes that occur when a substance melts. 

Forces of attraction within solids. 

The reading and interpretation of phase diagrams. 



243 www.ckl2.org 



Science Background Information 



This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Liquid Crystals 



www.ckl2.org 244 



245 www.ckl2.org 



Table 20.1: (continued) 



LCD or liquid crystal dis- 
plays have become a ubiq- 
uitous part of our technol- 
ogy landscape. Now appear- 
ing as computer and televi- 
sion screens and other elec- 
tronic displays, even in new 
automobile dashboard de- 
vices. Yet for chemistry 
students with an alert ear, 
the seemingly contradictory 
term Liquid Crystal, should 
at very least, merit addi- 
tional questions. We know 
that crystalline lattices are 
structures characteristic of 
the solid phase, with atoms 
or ions limited in their posi- 
tions to vibrational motion, 
in place of the translational 
capabilities due to the de- 
crease in intermolecular at- 
tractive forces in the liquid 
state. 




(Source: http: //commons . 
wikimedia. org/wiki/ 
File : E0S_rear.jpg Li- 
cense: CC-BY-SA) 



Table 20.1: 



LCD or liquid crystal dis- 
plays have become a ubiq- 
uitous part of our technol- 
ogy landscape. Now appear- 
ing as computer and televi- 
sion screens and other elec- 
tronic displays, even in new 
automobile dashboard de- 
vices. Yet for chemistry 
students with an alert ear, 
the seemingly contradictory 
term Liquid Crystal, should 
at very least, merit addi- 
tional questions. We know 
that crystalline lattices are 
^Wftc^uVis° r aiaracteristic of 
the solid phase, with atoms 
or ions limited in their posi- 
tions to vibrational motion, 
in place of the translational 



246 




-.Vm-IUiV 



A-.,, 



+u, 



Table 20.1: (continued) 



LCD or liquid crystal dis- 
plays have become a ubiq- 
uitous part of our technol- 
ogy landscape. Now appear- 
ing as computer and televi- 
sion screens and other elec- 
tronic displays, even in new 
automobile dashboard de- 
vices. Yet for chemistry 
students with an alert ear, 
the seemingly contradictory 
term Liquid Crystal, should 
at very least, merit addi- 
tional questions. We know 
that crystalline lattices are 
structures characteristic of 
the solid phase, with atoms 
or ions limited in their posi- 
tions to vibrational motion, 
in place of the translational 
capabilities due to the de- 
crease in intermolecular at- 
tractive forces in the liquid 
state. 




(Source: http: //commons . 
wikimedia. org/wiki/ 
File : E0S_rear.jpg Li- 
cense: CC-BY-SA) 



Due to their unusual struc- 
tural arrangements, liquid 
crystals exhibit interesting 
thermal, optical, and elec- 
tronic properties. Some liq- 
uid crystal samples will re- 
act to changes in tempera- 
ture. You may have used a 
body thermometer that dis- 
play the temperature with 
a liquid crystal. Pres- 

sure-sensitive liquid crystals 
have been implemented in 
the design of fingerprint de- 
tection devices. More com- 
monly, the application of an 
electric or magnetic field can 
result in the realignment of a 
liquid crystal sample which 
in turn causes a change in 
the visual display. Most 
nematic liquid crystals are 




247 



(Source: http:// 

commons . wikimedia . org/ 
wiki/File : 479563754_ 
8ef 9e978a7 . jpf ^ilfc 
Public Domain) 






Table 20.1: (continued) 



LCD or liquid crystal dis- 
plays have become a ubiq- 
uitous part of our technol- 
ogy landscape. Now appear- 
ing as computer and televi- 
sion screens and other elec- 
tronic displays, even in new 
automobile dashboard de- 
vices. Yet for chemistry 
students with an alert ear, 
the seemingly contradictory 
term Liquid Crystal, should 
at very least, merit addi- 
tional questions. We know 
that crystalline lattices are 
structures characteristic of 
the solid phase, with atoms 
or ions limited in their posi- 
tions to vibrational motion, 
in place of the translational 
capabilities due to the de- 
crease in intermolecular at- 
tractive forces in the liquid 
state. 




(Source: http: //commons . 
wikimedia. org/wiki/ 
File : E0S_rear.jpg Li- 

cense: CC-BY-SA) 



The current popularity 
of devices containing liq- 
uid crystals continues to 
grow as the demand for 
light-weight, flexible dis- 
play technology increases. 
Some future uses for this 
technology include the 
incorporation of liquid crys- 
tals into carbon nanotubes 
to create three-dimensional 
arrays. Another interesting 
potential application of 
liquid crystals includes their 
use in an anti-cancer drug, 
as well as the use of liquid 
crystals in cosmetics and 
^MriaPcm products. 



248 



Table 20.1: (continued) 



LCD or liquid crystal dis- 
plays have become a ubiq- 
uitous part of our technol- 
ogy landscape. Now appear- 
ing as computer and televi- 
sion screens and other elec- 
tronic displays, even in new 
automobile dashboard de- 
vices. Yet for chemistry 
students with an alert ear, 
the seemingly contradictory 
term Liquid Crystal, should 
at very least, merit addi- 
tional questions. We know 
that crystalline lattices are 
structures characteristic of 
the solid phase, with atoms 
or ions limited in their posi- 
tions to vibrational motion, 
in place of the translational 
capabilities due to the de- 
crease in intermolecular at- 
tractive forces in the liquid 
state. 




(Source: http: //commons . 
wikimedia. org/wiki/ 
File : E0S_rear.jpg Li- 
cense: CC-BY-SA) 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of The Solid State. 
60 Minute Class Periods per Lesson 

Table 20.2: 



Lesson 



Number of Class Periods 



20.1 Molecular Arrangement in Solids Con- 0.5 
trols Solid Characteristics 

20.2 Melting 1.0 



249 



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Table 20.2: (continued) 



Lesson Number of Class Periods 



20.3 Types of Forces of Attraction for Solids 0.5 

20.4 Phase Diagrams 0.5 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for The Solid State. 

The Solid State Materials List 

Table 20.3: 

Lesson Strategy or Activity Materials Needed 

20.1 Engagement Activity Plastic sandwich bags and 

cornstarch 
20.2 
20.3 
20.4 

Multimedia Resources 

You may find these additional web based resources helpful when teaching The Solid State: 

• Lesson on Characteristics of Solids, Liquids, and Gases: http: //www. chem.purdue . 
edu/gchelp/liquids/character . html 

• Phase Diagram Learning Activity: http://www.wisc-online.com/objects/index_ 
tj .asp?objID=GCH6304 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 



www.ckl2.org 250 



also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in The Solid State 

Table 20.4: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

20.1 

20.2 7d 

20.3 

20.4 

20.2 Lesson 20.1~"0303The Molecular Arrangement in 
Solids Controls Solid Characteristics 

Key Concepts 

In this lesson, students explore the characteristics of solids. 

Lesson Objectives 

• The students will describe the molecular arrangement in solids. 

• The students will use the molecular arrangement in solids to explain the incompress- 
ibility of solids. 

• The students will use the molecular arrangement in solids to explain the low rate of 
diffusion in solids. 

• The students will use the molecular arrangement in solids to explain the ability of 
solids to maintain their shape and volume. 

Lesson Vocabulary 
Strategies to Engage 

• Give each student a plastic sandwich bag that contains one cup of cornstarch. Ask 
students to add one cup of water to the solid and knead the material in the bag for 

251 www.ckl2.org 



three minutes. Draw four columns on the board. Have each student tell whether they 
think the material is a solid, liquid, either, or neither, and place their reasoning in the 
appropriate column. 

Strategies to Explore 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space in 
between. As you explore the lesson, have students write the "answer" to each objective. 

Strategies to Extend and Evaluate 

• Encourage interested students to research liquid crystal technology. Students should 
be prepared to share their findings with their classmates. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 20.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



20.3 Lesson 20.2 ~"0303Melting 
Key Concepts 

In this lesson, students explore energy changes that occur when a substance melts. 

Lesson Objectives 

• The students will explain why it is necessary for a solid to absorb heat during melting 
even though no temperature change is occurring. 

• Given appropriate thermodynamic data, the students will calculate the heat required 
to raise temperatures of a given substance with no phase change. 



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• Given appropriate thermodynamic data, the students will calculate the heat required 
to melt specific samples of solids with no temperature change. 

• Given appropriate thermodynamic data, the students will calculate the heat required 
to produce both a phase change and a temperature change, for a given sample of solid. 

Lesson Vocabulary 

crystal A solid consisting of plane faces and having definite shape with the atoms arranged 
in a repeating pattern. 

freezing The phase change from liquid to solid. 

freezing point The temperature at which a liquid changes to a solid. 

fusion 

1. The change of a liquid to a solid. 

2. A nuclear reaction in which two or more smaller nuclei combine to form a single nucleus. 

heat of condensation The quantity of heat released when a unit mass of vapor condenses 
to a liquid at constant temperature. 

heat of fusion The quantity of heat released when a unit mass of liquid freezes to a solid 
at a constant temperature. 

heat of vaporization The quantity of heat absorbed when a unit mass of liquid vaporizes 
to a gas at constant temperature. 

joule A basic unit of energy in the SI system, equal to one Newton-meter. 

melting The phase change from solid to liquid. 

melting point The temperature at which a substance changes from the solid phase to the 
liquid phase. 

Strategies to Engage 

• Ask students what they already know about melting. Use this opportunity to gauge 
student understanding of the melting process and to clear up any misconceptions. 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

253 www.ckl2.org 



Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 



Strategies to Extend and Evaluate 

• Have students create a concept map of vocabulary terms. Tell students to relate 
vocabulary terms to the concepts explored in this lesson, and to correctly illustrate the 
relationships between the terms and the concepts. 



Lesson Worksheets 

Copy and distribute the Lesson 20.4 Worksheets, Heat Transfer and Calorimetry in the 

Supplemental Workbook. Ask students to complete the worksheets alone or in pairs as a 
review of lesson content. 



Review Questions 

Have students answer the Lesson 20.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



20.4 Lesson 20.3 ~"0303Types of Forces of Attraction 
for Solids 

Key Concepts 

In this lesson, students will learn the nature of the forces of attraction within solids. 



Lesson Objectives 

• The students will describe the metallic bond, and explain some of the solid character- 
istics that are due to metallic bonding. 

www.ckl2.org 254 



• Given characteristics of a solid such as conductivity of solid and liquid phase, solubility 
in water, malleability, and so on, the students will identify the type of solid, i.e. the 
attractive forces holding the solid in solid form. 

Lesson Vocabulary 

alloy A substance composed of a mixture of two or more elements and having metallic 
properties. 

conductivity The property of being able to transmit heat and/or electricity. 

conductor A substance that can transmit heat and/or electricity. 

ductility The property of a substance that allows it to be drawn into a wire. 

electrical conductivity The ability of a substance to transmit an electric current. 

malleable The property of being able to be hammered or rolled into sheets. 

metallic bond The attractive force that binds metal atoms together. It is due to the 
attractive force that the mobile electrons exert on the positive ions. 

specific heat The amount of energy necessary to raise 1.00 gram of a substance by 1.00°C. 

Strategies to Engage 
Strategies to Explore 

Ask students to look at Figure 4 and write a paragraph describing what is happening in the 
illustration. 

This lesson includes a description of different types of solids. Before reading, prepare less 
proficient readers by having students write the following on the top of separate sheets of 
notebook paper: 

• Ionic Solids 

• Metallic Solids 

• Network Solids 

• Amorphous Solids 

255 www.ckl2.org 



As they read each section have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

Strategies to Extend and Evaluate 

• Have students work in pairs or teams to write a poem about solids. Their poems should 
explain what solids are and the types of forces of attraction for solids. 

• Have students use grid paper to make a crossword puzzle using the vocabulary terms. 
Ask students to exchange papers with a classmate and solve each other's puzzles. 

Lesson Worksheets 

Review Questions 

Have students answer the Lesson 20.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

20.5 Lesson 20.4~"0303Phase Diagrams 
Key Concepts 

In this lesson, students will explore the reading and interpretation of phase diagrams. 

Lesson Objectives 

• The students will read specific requested information from a phase diagram. 

• The students will state the primary difference between a generic phase diagram, and 
a phase diagram for water. 

Lesson Vocabulary 

critical pressure The pressure required to liquefy a gas at its critical temperature. 
www.ckl2.org 256 



critical temperature The highest temperature at which it is possible to liquefy the sub- 
stance by increasing pressure. 

Strategies to Engage 

• Explain to students that in this lesson, they will learn how to show the relationships 
among the solid, liquid, and vapor states of a substance in one simple diagram. 

Strategies to Explore 

• Use Figure 11 to explain as many concepts as possible. Relate concepts such as critical 
temperature and critical pressure to Figure 11. DI (ELL) 

Strategies to Extend and Evaluate 

• On the board or chart paper, have students write a class summary of this lesson. Have 
one student come up with the first sentence and have students contribute sentences 
until the entire lesson has been summarized. 



Lesson Worksheets 

Review Questions 

Have students answer the Lesson 20.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 20 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 20 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



25 7 www.ckl2.org 



www.ckl2.org 258 



Chapter 21 



TE The Solution Process 



21.1 Unit 7 Solutions and Their Behavior 



Outline 

This unit, Solutions and Their Behavior, includes two chapters that cover the solution process 
and the behavior of ions in solution. 



• Chapter 21 The Solution Process 

• Chapter 22 Ions in Solution 



Overview 



The Solution Process 

This chapter describes solvation, concentration calculations, solubility, and colligative prop- 
erties of solutions. 

Ions in Solution 

This chapter covers dissociation, electrolytes and non-electrolytes, reactions between ions in 
solution, and ionic and net-ionic equations. 



259 www.ckl2.org 



21.2 Chapter 21 The Solution Process 
Outline 

This chapter, The Solution Process, consists of nine lessons that cover solvation, concentra- 
tion calculations, solubility, and colligative properties of solutions. 

Lesson 21.1 What are Solutions? 

Lesson 21.2 Why Solutions Occur 

Lesson 21.3 Solution Terminology 

Lesson 21.4 Measuring Concentration 

Lesson 21.5 Solubility Graphs 

Lesson 21.6 Factors Affecting Solubility 

Lesson 21.7 Colligative Properties 

Lesson 21.8 Colloids 

Lesson 21.9 Separating Mixtures 

Overview 

In these lessons, students will explore: 

The composition of solutions. 

The relationship between molecular structure and solution formation. 

Vocabulary associated with solutions. 

Methods of expressing solution concentration. 

The information provided by a solubility graph. 

The factors that affect the solubility of solids and gases. 

The colligative properties of solutions. 

The similarities and differences among solutions, colloids, and suspensions. 

Methods used to separate mixtures. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Solutions 

We are all familiar with the phenomenon of a hard crystalline solid, like table salt, when 
placed in water, apparently disappearing quite quickly. The crystalline structure breaks up 
and the particles enter into the water. Why does this process occur? 

www.ckl2.org 260 



More questions arise when we think about dissolving and solutions. Table salt, for example, 
dissolves in water, but it will not dissolve in benzene. Camphor, on the other hand, dissolves 
easily in benzene, but not in water. While other substances like diamonds or graphite will 
not dissolve in any liquid. What controls whether a solid dissolves, and in what solvent it 
will dissolve? 

Ion-Ion Attraction vs. Ion-Solvent Attraction 

Consider the example of salt dissolving in water. Recall that table salt (sodium chloride) 
has a simple crystal structure in which positive sodium ions and negative chloride ions are 
organized in a crystal lattice. The electrical interactions between the positive and negative 
ions causes them to be strongly held at their locations in the crystal. To break up the crystal 
requires a large amount of energy, or else the attraction between the ions must be replaced 
by some other equal or greater attraction. This is the key to understanding what happens 
when the ions dissolve in water. The attraction between the ions in the solid is replaced 
by an attraction between the ions and the water molecules (or other solvent molecules). 
Water is a polar liquid. The oxygen end of the molecule has a partial negative charge, while 
the hydrogen end has a partial positive charge. When the sodium ion enters the liquid 
water, the water molecules cluster around it so that the partially negative ends of the water 
molecules are next to the positive sodium ions. Similarly the water molecules cluster around 
the chloride ions so that the partially positive ends of water molecules are directed toward 
the negative charge of the chloride ions. It is these ion- water attractions in the solution that 
replace the ion-ion attractions in the solid. The ions can break away from their oppositely 
charged neighbors in the crystal because they have found equal or stronger attractions in the 
solution. High solubility requires that the attraction between the atoms, ions, or molecules 
in the dissolving solid be replaced by equivalent or greater attractions between these particles 
and the molecules of the solvent. In many cases, it still requires an input of energy for a solid 
to dissolve in a solvent, but if the requirement is small enough, its effect can be outweighed 
by that of the increased disorder of the solution. The process is then driven by the increased 
entropy of the solution. 

Like Dissolves Like 

Solids like salt, which consist of ions, dissolve in polar solvents like water in which the solvent 
molecules have dipoles, because the electrical attractions between the ions and the solvent 
replace those between ions in the solid. In crystals made of non-polar molecules like camphor, 
the forces are different. The molecules are held in the crystal by weak London dispersion 
force attractions. Similar forces exist between the molecules in a solvent like benzene. So 
again, the interactions between the molecules in the solid can be replaced by those between 
the solute molecule and solvent molecules. Hence, camphor dissolves in benzene. 

Much of what we have described so far relates to water as a solvent. Water is the most 
widespread liquid on the surface of earth. As we have seen, water is also an excellent solvent 
for polar solids. Polar solids include not only those that are made of ions like sodium 
chloride, but also those that are composed of polar molecules, like glucose and alcohol. In 

261 www.ckl2.org 



some cases, the attractions between solute molecules and the solvent water are even greater 
due to hydrogen bonding. 

Molecules or parts of molecules can be classified as hydrophilic (water loving) or hydrophobic 
(water hating) depending on whether they contain polar groups. An important group of 
molecules of this type are soaps and detergents, which have both hydrophilic and hydrophobic 
ends, leading to a range of useful and remarkable properties. 

Solid Solutions 

We do not normally think of solids like copper or silicon as being able to dissolve because 
there are no common liquids in which these solids will dissolve. Sometimes, the reaction 
between metals and strong acids are referred to as "dissolving", but that involves a chemical 
reaction. In order for a solid to dissolve, the interaction between the atoms or molecules 
in the solid must be replaced by comparable ones in the solution. There are no substances 
which are liquids at normal temperatures, in which the atoms or molecules attract metal 
atoms strongly enough to dissolve them (assuming no chemical reaction). 

It is possible, however, for these solids to dissolve in other solids forming solid solutions. 
Copper will dissolve in zinc to form an alloy (a solution of one metal in another) known as 
brass. Like most alloys, brass is crystalline, that is, it has a regular arrangement of metal 
atom locations with some of the locations occupied by copper and some by zinc atoms. 
Alloy formation is very common; other examples are pewter (tin and zinc) and bronze (iron 
and copper). Dissolving a small amount of one metal in another can also have significant 
effects on physical and chemical properties. Stainless steel is essentially iron into which a 
small amount of chromium is dissolved. Stainless steel is significantly different from iron in 
terms of the rate at which it corrodes. Alloying iron with copper in bronze results in a much 
tougher, less brittle material. Solid solutions are widespread. Silicon, as we have seen, will 
not dissolve in any common liquid; but it will dissolve in germanium (a solid with the same 
crystal structure) in much the same way that copper dissolves in zinc. These solids further 
illustrate the point that dissolving small amounts of one solid substance in another is a vitally 
important way of altering the properties of materials. One that is used on an enormous scale 
in contemporary technology. The classic example is the semiconductor silicon. Dissolving 
tiny amounts (less than one part per million) of phosphorus in silicon has a significant 
effect on its ability to conduct electricity (making the material that is known as an 'n-type' 
semiconductor). Similar amounts of arsenic dissolved in silicon have equally large effects, but 
result in different electrical characteristics (the material becomes a 'p-type' semiconductor). 
Putting the two types of material together creates the famous p/n junction which allows 
electricity to flow only in one direction, a vital feature of some electrical circuits. Silicon 
with tiny quantities of deliberately introduced impurities is therefore the material basis of 
the technology on which the modern electronics revolution is based. 



www.ckl2.org 262 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of The Solution 
Process. 



60 Minute Class Periods per Lesson 



Table 21.1: 



Lesson 



Number of Class Periods 



21.1 What Are Solutions 

21.2 Why Solutions Occur 

21.3 Solution Terminology 

21.4 Measuring Concentration 

21.5 Solubility Graphs 

21.6 Factors Affecting Solubility 

21.7 Colligative Properties 

21.8 Colloids 

21.9 Separating Mixtures 



0.5 
1.0 
1.0 
2.0 
1.0 
1.0 
1.5 
0.5 
1.5 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for The Solution Process. 



The Solution ProcessMaterials List 



Table 21.2: 



Lesson 



Strategy or Activity 



Materials Needed 



21.1 

21.2 
21.3 
21.4 
21.5 
21.6 
21.7 



Engagement Activity 



Engagement Activity 
Exploration Activity 



Vinegar, 
beakers 



vegetable oil, 



20 oz. bottles of soda 
Quart sized Ziploc bags, gal- 
lon sized Ziploc bags, milk, 
sugar, vanilla, salt, ice 



263 



www.ckl2.org 



Table 21.2: (continued) 



Lesson Strategy or Activity Materials Needed 

21.8 Engagement Activity Several solutions and col- 

loids, beakers, black con- 
struction paper, and flash- 
light 

21.9 Exploration Activity Paper towels, straws, cups 



Multimedia Resources 

You may find these additional web based resources helpful when teaching The Solution 
Process: 

• Virtual mixtures lab: http : //www . harcourtschool . com/activity/mixture/mixture . 
html 

• Cleaning water activity: http : //acswebcontent . acs . org/games/clean_water . html 

• Lesson on the factors affecting solubility: http : //www . chem . lsu . edu/lucid/tutorials/ 
solubility/Solubility . html 

Possible Misconceptions 

Identify: Students may think that the solubility of solid solute in a liquid solvent always 
increases with temperature. 

Clarify: There are some exceptions to this trend. 

Promote Understanding: Add 40g of calcium acetate to lOOmL of water. Heat the solution 
until the calcium acetate precipitates out of the solution. Add ice to the solution, and the 
solution will redissolve. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in The Solution Process 



www.ckl2.org 264 



Table 21.3: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

21.1 

21.2 6b 

21.3 6a 

21.4 6d 

21.5 6c 

21.6 6c 

21.7 6e 
21.8 

21.9 6f 



21.3 Lesson 21.1 ~"0303The Solution Process 
Key Concepts 

In this lesson, students explore the composition of solutions. 



Lesson Objectives 

• Define solutions. 

• Describe the composition of homogeneous solutions. 

• Describe the different types of solutions that are possible within the three states of 
matter. 

• Identify homogeneous solutions of different types. 



Lesson Vocabulary 

solution A homogenous mixture; composition can vary; but composition is the same 
throughout once the solution is made. 



Strategies to Engage 

• Ask students to give examples of solutions. If students only give examples of solutions 
in solids, explain to them that solutions are possible with other states of matter as 
well. 



265 www.ckl2.org 



Strategies to Explore 

• Challenge students to fill in Table 1 with as many examples of actual solutions as they 
can think of. Award a prize to the student who can come up with the most (correct) 
examples. 



Strategies to Extend and Evaluate 

• Have each student record the four sentences in this section that most clearly represent 
the main ideas. Read key sentences in the text and have students raise their hands 
if they have recorded that sentence. Facilitate a discussion in which students defend 
their selections. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 21.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



21.4 Lesson 21.2 ~"0303Why Solutions Occur 
Key Concepts 

In this lesson students explore the relationship between molecular structure and solution 
formation. 



Lesson Objectives 

• Describe why solutions occur; the "like dissolves like" generalization. 

• Determine if solutions will occur by studying the molecular structure. 

• State the importance of water as the "universal solvent." 

www.ckl2.org 266 



Lesson Vocabulary 

intermolecular bonds Forces of attraction between molecules. 
intramolecular bonds Forces of attraction between atoms in a molecule. 
universal solvent A solvent able to dissolve practically anything (water). 

Strategies to Engage 

• Add a few drops of vinegar to a beaker of water, then add a few drops of vegetable oil 
to another beaker of water. Students should notice that the vinegar mixes with the 
water to form a solution while the vegetable oil does not. Facilitate a discussion with 
students in which they attempt to explain this occurrence. Explain to students that 
in this lesson, they will find out why this occurs. 

Strategies to Explore 

• Have students write a paragraph explaining Figure 1. Tell students to include the 
vocabulary terms in their explanations. 

• Have students write a paragraph explaining Figure 1 in terms of the kinetic molecular 
theory. 

• Explain to students that solutions in which water is the solvent are called aqueous 
solutions. 

Strategies to Extend and Evaluate 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 21.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

26 7 www.ckl2.org 



21.5 Lesson 21.3 Solution Terminology 
Key Concepts 

In this lesson students explore vocabulary associated with solutions. 



Lesson Objectives 

• Students will define solute, solvent, soluble, insoluble, miscible, immiscible, saturated, 
unsaturated, concentrated, and dilute. 



Lesson Vocabulary 

solute The substance in a solution present in the least amount. 

solvent The substance in a solution present in the greatest amount. 

soluble The ability to dissolve in solution. 

insoluble The inability to dissolve in solution. 

miscible Two liquids having the ability to be soluble in each other. 

immiscible Two liquids not having the ability to be soluble in each other. 



saturated A solution holding the maximum amount of solution in a given amount of 
solvent. 



unsaturated A solution holding less than the maximum amount of solution in a given 
amount of solvent. 



concentrated A solution where there is a large amount of solute in a given amount of 
solvent. 



dilute A solution where there is a small amount of solute in a given amount of solvent. 
www.ckl2.org 268 



Strategies to Engage 

• Preview the lesson vocabulary to find out what your students already know about the 
concepts to be explored in this lesson. Have students define each vocabulary term. At 
the end of the lesson encourage students to go back and write the correct definition for 
each incorrect definition. 



Strategies to Explore 

• Have students research the Latin word miscere and write a paragraph relating it to the 
terms "miscible" and " immiscible". 



Strategies to Extend and Evaluate 

• Have students write questions derived from Bloom's Taxonomy. Instruct students to 
research Bloom's Taxonomy and write and answer one question from each of the six 
levels: knowledge, comprehension, application, analysis, synthesis, and evaluation. 

• Ask each student to choose a set of vocabulary terms such as solvent and solute, soluble 
and insoluble, miscible and immiscible, saturated and unsaturated, concentrated and 
dilute, and create a poster comparing and contrasting the two terms. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 21.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



21.6 Lesson 21.4 Measuring Concentration 
Key Concepts 

In this lesson students learn methods of expressing solution concentration. 

269 www.ckl2.ore 



Lesson Objectives 

• Define molarity, mass percent, ppm, and molality. 

• Calculate molarity, mass percent, ppm, and molality 

• Explain the importance of quantitative measurement in concentration. 

Lesson Vocabulary 

molarity A concentration unit measuring the moles of solute per liter of solution. 

mass percent A concentration unit measuring the mass of solute per mass of solution. 
This unit is presented as a percent. 

weight percent Another name for mass percent. 

parts per million (ppm) A concentration unit measuring the mass of solute per mass of 
solution multiplied by 1 million. 

molality A concentration unit measuring the moles of solute per kilograms of solutions. 

Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

Strategies to Explore 

• Divide students into groups of three or four to work on problems in this lesson. 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

• Facilitate a discussion with students in which they compare and contrast the methods 
of expressing solution concentration explored in this lesson. 

Strategies to Extend and Evaluate 

• Have students use grid paper to make a crossword puzzle using the vocabulary terms. 
Ask students to exchange papers with a classmate and solve each other's puzzles. 

www.ckl2.org 270 



Review Questions 

Have students answer the Lesson 21.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



21.7 Lesson 21.5 Solubility Graphs 
Key Concepts 

In this lesson students explore the information provided by a solubility graph. 

Lesson Objectives 

• Students will read and report data from solubility graphs. 

• Students will read and report saturation points from a solubility graph. 

Lesson Vocabulary 

solubility The amount of solute that will dissolve in a given amount of solvent at a par- 
ticular temperature. 

solubility graph A solubility graph is drawn to display the solubility at different temper- 
atures. It is the mass of the solute/100 g of H 2 versus temperature in °C. 

Strategies to Engage 
Strategies to Explore 

• Use the graphical nature of this lesson to reduce the reliance on language skills. As 
you go through each example problem, use the graphs to explain the concepts explored 
in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• Have students write a lesson to teach someone how to read a solubility graph. Tell 
students to include examples of each key concept. 

271 www.ckl2.org 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 21.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

21.8 Lesson 21.6 Factors Affecting Solubility 
Key Concepts 

In this lesson students learn the factors that affect the solubility of solids and gases. 



Lesson Objectives 

• Describe the factors that affect solid solubility. 

• Describe the factors that affect gas solubility. 

• Describe how pressure can affect solubility. 



Lesson Vocabulary 

Henry's Law At a given temperature the solubility of a gas in a liquid is proportional to 
the pressure of that gas. 



Strategies to Engage 

• Have students observe 20oz bottles of warm and cold soda. Because the warm soda 
has less dissolved carbon dioxide, Students should notice that the warm soda has more 
space above the liquid and it may be a little wider. Open each bottle. Students should 
notice that the warm soda has a louder fizzing sound and more bubbles. Explain to 
students that by the end of this lesson they will be able to explain these occurrences. 

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Strategies to Explore 

• Have groups of students design and conduct a scientific investigation on the effect of 
temperature and surface area on the solubility of sugar. Instruct students to come up 
with a list of necessary materials and equipment, and to write a step-by-step procedure. 
After the materials and procedure has been approved, have the groups conduct their 
investigations, and then write a lab report. 

Strategies to Extend and Evaluate 

• Challenge interested students to research the effects of thermal pollution on aquatic 
life and relate it to the concept of solubility. Students should be prepared to share 
their findings with the class. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 21.6 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



21.9 Lesson 21.7 Colligative Properties 
Key Concepts 

In this lesson students learn the colligative properties of solutions and practice calculations 
involving them. 

Lesson Objectives 

• Describe vapor pressure lowering. 

• Define boiling point elevation and freezing point depression. 

• Describe what happens to the boiling points and freezing points, when a solute is added 
to a solvent. 



27 3 www.ckl2.org 



• Describe the importance of the Van't Hoff factor. 

• Calculate the boiling point elevation for electrolyte and non-electrolyte solutions. 

• Calculate the freezing point depression for electrolyte and non-electrolyte solutions. 

Lesson Vocabulary 

boiling point elevation The difference in the boiling points of the pure solvent from the 
solution. 

freezing point depression The difference in the freezing points of the solution from the 
pure solvent. 

Van't Hoff factor The number of particles that the solute will dissociate into upon mixing 
with the solvent 

Strategies to Engage 

• Ask students why they think salt is used to melt ice on roads and sidewalks. Use this 
opportunity to gauge student understanding, clear up misconceptions, and generate 
curiosity for the concepts explored in this lesson. 

Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI(LPR) 

• Divide students into groups of three or four to work on problems in this lesson. 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

• Have students work in pairs to make ice cream by following the following procedure: 
Add 1/4 cup sugar, 1/2 cup milk, and 1/4 teaspoon vanilla to a quart size Ziploc bag 
and seal the bad securely. Put 2 cups of ice into a gallon Ziploc bag and measure and 
record its temperature. Add 1/2 cup of salt to the bag and measure and record the 
temperature again. Place the quart Ziploc bag inside of the gallon bag and seal the 
gallon bag. Gently massage the bag for about 25 minutes. During the mixing process, 
facilitate a discussion with students about why the temperature of the ice/salt mixture 
was lower than the ice alone. 

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Strategies to Extend and Evaluate 

• Have students bring in examples of applications of colligative properties in everyday 
life; such as adding salt to water in order to increase its boiling point while cooking. 
Students should be prepared to share their findings with the rest of the class. 



Review Questions 

Have students answer the Lesson 21.7 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



21.10 Lesson 21.8 Colloids 
Key Concepts 

In this lesson students explore the similarities and differences among solutions, colloids, and 
suspensions. 



Lesson Objectives 

• Define colloids and suspensions. 

• Compare solutions, colloids, and suspensions. 

• Characterize solutions as suspensions, colloids, or solutions. 

• Name some common examples of colloids. 



Lesson Vocabulary 

colloid Mixtures where the size of the particles is between 1 x 10 3 pm and 1 x 10 6 pm (i.e., 
milk). 

suspension Mixtures where the particles settles to the bottom of the container and can 
be separated by filtration. 



Tyndall Effect Involves shining a light through the mixture, if the light scatters, the 
mixture is a colloid. 



27 5 www.ckl2.org 



Strategies to Engage 

• Place several solutions (such as salt/water and soda) and colloids (such as milk and 
cornstarch/water), into separate beakers. Label each beaker with the name of the 
material it contains. Make a cone from black construction paper and tape it over the 
lens of a flashlight. Turn off the lights in the room and shine the narrow beam of light 
at each of the beakers. The beam of light will be visible in the colloids, but will not 
be visible in the solutions. Tell the students that by the end of this lesson they will be 
able to explain these occurrences. 



Strategies to Explore 

• Point out to students that the main difference between solutions, colloids, and suspen- 
sions is the size of the particles. Solutions have the smallest particle size, followed by 
colloids. Suspensions have the largest particle size. 



Strategies to Extend and Evaluate 

• Have students organize the information explored in this lesson into a table that sum- 
marizes the properties of solutions, colloids, and suspensions. Ask students to include 
examples of each and other information such as particle size and Tyndall effect. 



Have students create a poster that includes examples of edible solutions, colloids, and 
suspensions. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 21.8 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



www.ckl2.org 27 6 



21.11 Lesson 21.9 Separating Mixtures 
Key Concepts 

In this lesson students explore methods used to separate mixtures. 

Lesson Objectives 

• The students will describe differences between the physical properties of pure sub- 
stances and solutions. 

• The students will list and describe methods of separation for mixtures. 

• The students will explain the principles involved in chromatographic separation. 

• The students will identify the mobile and stationary phases in a chromatography de- 
sign. 

• Given appropriate data, the students will calculate Rf values. 

Lesson Vocabulary 

distillation The evaporation and subsequent collection of a liquid by condensation as a 
means of purification. 

fractional distillation This is a special type of distillation used to separate a mixture of 
liquids, using their differences in boiling points. 

chromatography Any of various techniques for the separation of complex mixtures that 
rely on the differential affinities of substances for a mobile solvent and a stationary 
medium through which they pass. 

Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

Strategies to Explore 

• Students can perform this simple chromatography experiment using a paper towel, a 
black washable marker, a straw, and a cup. Use the marker to draw a circle on the 
paper towel. Use a straw to add drops of water to the center of the circle. Students 
should be able to see the individual colors in the ink. Encourage students to perform 

277 www.ckl2.org 



the experiment again using different materials such as a coffee filter instead of a paper 
towel, alcohol instead of water, and drink mix instead of a marker. 

Have students create a chart that summarizes each of the separation methods explored 
in this lesson. 



Strategies to Extend and Evaluate 

• As a class, create a concept map of the information explored in this chapter. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 21.9 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 21 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 21 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 27 8 



Chapter 22 



TE Ions in Solution 



22.1 Chapter 22 Ions in Solutions 
Outline 

This chapter, Ions in Solution consists of three lessons that cover dissociation, electrolytes 
and non-electrolytes, reactions between ions in solution, and ionic and net-ionic equations. 

• Lesson 22.1 Ionic Solutions 

• Lesson 22.2 Covalent Compounds in Solution 

• Lesson 22.3 Reactions Between Ions in Solutions 

Overview 

In these lessons, students will explore: 

• What happens when ionic solids dissolve in water. 

• What happens when covalent compounds dissolve in water. 

• Solubility and the reactions between ions in solutions. 

Science Background Information 

This background information is provided for teachers who are just beginning to teach in this 
subject area. 

Modern Armor from a Solution 

2/9 www.ckl2.org 



Stephanie Kwolek graduated from the women's college of a much larger all-men's university. 
(Today, the two colleges form the co-ed Carnegie Mellon University.) With her degree in 
chemistry, Kwolek accepted a job at the DuPont Chemical Company. DuPont had been 
highly successful with its development of Nylon®, Dacron®, and other synthetic fibers and 
in the early 1960's, Kwolek was working on the development of new fibers. The process for 
developing new fibers at that time was to combine substances to make a polymer, melt the 
polymer into a liquid, and then spin the liquid in a machine called a "spineret". The liquid 
would squirt out through holes in the spineret and solidify into fibers. 

Kwolek was directed to search specifically for high-performance fibers that were very stiff 
and strong and could be used to reinforce tires in place of steel wires. Lightweight fibers 
that were stiff and strong and resistant to high temperatures would have many profitable 
applications. 

One day, Kwolek was experimenting with a polymer that was extremely difficult to melt 
and therefore couldn't be "spun" in the spineret. Kwolek decided to find a solvent that 
would dissolve the polymer and get it into liquid form in that manner, rather than melt it. 
After many tries, she eventually found a solvent that would dissolve the polymer. She had 
difficulty convincing the scientist who ran the spineret to "spin" her solution, because he 
felt that the solution would plug the holes in his machine. After several days, Kwolek finally 
convinced him to spin her solution. The solution spun beautifully and produced fibers that 
were very strong and very stiff. Kwolek baked the fibers and after baking, they were even 
stronger and stiffer. 

Kwolek had made two discoveries. The solution she had produced was a new type of sub- 
stance called liquid crystal solutions, and the fiber she had produced was a new kind of fiber 
called an aramid fiber. Para-aramid fibers go by the commercial name Kevlar®. 

Today, aramid fibers are used to make bullet-resistant vests, boat hulls, coats, cut-resistant 
gloves, fiber-optic cables, firefighters' suits, fuel hoses, helmets, parts of airplanes, radial 
tires, special ropes, pieces of spacecraft, tennis rackets, canoes, and skis. Aramid fibers are 
stronger and lighter than steel. A vest made of seven layers of aramid fiber weighs about 
2.5 pounds and can deflect both knife blades and bullets fired from a distance of 10 feet. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Ions in Solution. 
60 Minute Class Periods per Lesson 



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Table 22.1: 



Lesson Number of Class Periods 



21.1 Ionic Solutions 0.5 

21.2 Covalent Compounds in Solution 0.5 

21.3 Reactions Between Ions in Solu- 1.5 
tion 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Ions in Solution. 

Ions in Solution Materials List 

Table 22.2: 

Lesson Strategy or Activity Materials Needed 

22.1 
22.2 
22.3 

Multimedia Resources 
Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Ions in Solution 



281 www.ckl2.org 



Table 22.3: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



22.1 
22.2 
22.3 



22.2 Lesson 22.1 Ions in Solution 

Key Concepts 

In this lesson students explore what happens when ionic solids dissolve in water. 

Lesson Objectives 

• Describe electrostatic attraction. 

• Explain how ionic solids attract water molecules when they dissolve in water. 

• Explain the difference between physical changes and chemical changes. 

• Define electrolyte solutions and be able to identify electrolytes. 

Lesson Vocabulary 

electrostatic attraction When solids form from a metal atom donating an electron (thus 
forming a positive cation) to a non-metal (thus forming a negative anion) the two ions 
in the solid are held together by the attraction of oppositely charged particles. 

chemical changes Changes that occur with the chemical bonding where a new substance 
is formed. 

physical changes Changes that occur in the physical structure but do not occur at the 
molecular level. 

electrolyte solutions Solutions that contain ions that are able to conduct electricity. 

Strategies to Engage 

• Ask students to describe what happens when an ionic compound dissolves in water. 
Use this opportunity to gauge student understanding, address misconceptions, and 

www.ckl2.org 282 



generate curiosity for the concepts explored in this lesson. 

Strategies to Explore 

• Use Figure 4 to explain as many concepts as possible. Relate concepts such as electro- 
static attraction and dissociation to Figure 18. DI (ELL) 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI (LPR) 

Strategies to Extend and Evaluate 

• Challenge students to come up with their own question for each of the sections in this 
lesson. Students may then exchange papers with a classmate to have them answer each 
others questions. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 22.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



22.3 Lesson 22.2 Covalent Compounds in Solution 
Key Concepts 

In this lesson students explore what happens when covalent compounds dissolve in water. 

Lesson Objectives 

• Describe intermolecular bonds. 

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• Explain why molecules stay together when dissolving in solvents. 

• Define and explain non-electrolytes. 

Lesson Vocabulary 

intermolecular bonding The bonding that occurs between molecules. 
non-electrolytes Solutions that do not conduct electricity. 

Strategies to Engage 

• Introduce lesson concepts by asking students to recall what they know about the simi- 
larities and differences between ionic and covalent compounds. Guide them in focusing 
their prior knowledge. 

Strategies to Explore 

• Ask students to look at Figure 2 and write a paragraph to describe what is happening 
in the illustration. Instruct students to demonstrate mastery of each lesson objective 
in their paragraph. 

Strategies to Extend and Evaluate 

• Have each student record the four sentences in this section that most clearly represent 
the main ideas. Read key sentences in the text and have students raise their hands 
if they have recorded that sentence. Facilitate a discussion in which students defend 
their selections. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 22.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



www.ckl2.org 284 



22.4 Lesson 22.3 Reactions Between Ions in Solutions 
Key Concepts 

In this lesson students explore solubility and the reactions between ions in solutions. 

Lesson Objectives 

• Use the solubility chart and/or solubility rules to determine if substances are soluble 
in water. 

• Use the solubility chart and/or the solubility rules to determine if precipitates will 
form. 

• Write molecular, ionic, and net ionic equations. 

• Identify spectator ions in ionic equations. 

Lesson Vocabulary 

solubility chart A grid showing the possible combinations of cations and anions and their 
solubilities in water. 

solubility rules A list of rules dictating which combinations of cations and anions will be 
soluble or insoluble in water. 

formula equation A chemical equation written such that the aqueous solutions are writ- 
ten in formula form. 

total ionic equation A chemical equation written such that the actual free ions are shown 
for each species in aqueous form. 

net ionic equation The overall reaction that results when spectator ions are removed 
from the ionic equation. 

spectator ions The ions in the total ionic equation that appear in the same form on both 
sides of the equation indicating they do not participate in the overall reaction. 

Strategies to Engage 
Strategies to Explore 

• Have students write step-by-step instructions for writing net ionic equations and use 
these steps to complete the practice problems in this lesson. 

285 www.ckl2.org 



Strategies to Extend and Evaluate 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 22.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 22 Assessment 

Provided to teachers upon request at teacher-requests@ckl2.org. 

Chapter 22 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 286 



Chapter 23 



TE Chemical Kinetics 



23.1 Unit 8 Chemical Kinetics and Equilibrium 
Outline 

This unit, Chemical Kinetics and Equilibrium, includes two chapters that explore reaction 
rates and equilibrium. 



• Chapter 23 Chemical Kinetics 

• Chapter 24 Chemical Equilibrium 



Overview 

Chemical Kinetics 

This chapter covers reaction rates and the factors that affect reaction rates. 

Chemical Equilibrium 

This chapter covers relationships between forward and reverse reaction rates, the concept of 
chemical equilibrium, the mathematics of the equilibrium constant, Le Chatelier's principle, 
and solubility product constant calculations. 

28 7 www.ckl2.org 



23.2 Chapter 23 Chemical Kinetics 
Outline 

This chapter Chemical Kinetics consists of five lessons that cover reaction rates and the 
factors that affect reaction rates. 



Lesson 23.1 Rate of Reactions 

Lesson 23.2 Collision Theory 

Lesson 23.3 Potential Energy Diagrams 

Lesson 23.4 Factors That Affect Reaction Rates 

Lesson 23.5 Reaction Mechanism 



Overview 

In these lessons, students will explore: 



The rates of chemical reactions. 

Reactions rates in terms of collisions between reacting particles. 

Potential energy diagrams for endothermic and exothermic reactions. 

The effect of temperature, surface area, concentration, and catalysts on the rate of a 

chemical reaction. 

Multi-step processes as well as the individual reactions in a multi-step process. 



Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Chemical Kinetics 

Chemical Kinetics is the study of the mechanisms and rates of chemical reactions. In order 
for a reaction to occur, a collision between reacting particles must occur. Assuming the 
reactant is a molecule, the atoms in the molecule are already bonded to at least one other 
atom. If the atom is to form new bonds during the reaction, the old bonds must first be 
broken. In some cases, the collision to break the old bonds must also have proper orientation. 
For example, consider the reaction between H2 and I2 shown below. 



www.ckl2.org 288 




B 




During the collision between H2 and I2, the H-H bond and the I-I bond (indicated by red 
arrows) must be broken and H-I bonds (indicated by green arrows) must be formed. In 
collision A, the side-to-side collision of the molecules would require the least amount of 
energy to break the old bonds and the atoms would be in convenient position to form HI 
molecules. In collision B, however, the end-to-end collision would appear to push the atoms 
together rather than break them apart, and the H and I atoms in the outside positions are 
not in convenient position to bond. If collision B were to result in a reaction, a great deal 
more energy would be required than that for collision A. 

Reaction rates are affected by the concentrations of the reacting species, the temperature of 
the reaction, and whether or not a catalyst is present. Reaction rates (at constant temper- 
ature) can be expressed in a mathematical expression relating the rate of a reaction to the 
concentrations of the reactants. This rate law can be determined from experimental data. 

Here is an example of an overall chemical reaction and the rate law for that reaction. 

2 NOfc) + Oaoo - 2 N0 2(g) 
Rate = k[NO] 2 [0 2 ] 

The rate expresses the rate of production of N0 2 in moles/liter/sec or M/s, and is propor- 
tional to the concentrations of the reactants where k is a proportionality constant called the 
reaction constant. The exponent associated with each reactant is referred to as the order 
of the reaction with respect to that reactant. In this case, the reaction is 2 nd order with 
respect to NO and 1 st order with respect to O2. The overall order of the reaction is the sum 
of partial orders with respect to each reactant. In this case, the overall order of the reaction 
is 3 rd order. 

The reaction mechanism is the series of collisions that describe the steps involved in the 
reaction. Consider the following reaction. CO + NO2 — > CO2 + NO 

In this reaction, it has been experimentally determined that this reaction takes place accord- 
ing to the rate law R = k[N02] 2 . Therefore, a possible mechanism by which this reaction 
takes place is: 

2 N0 2 -> N0 3 + NO~"0303T"0303(slow) 
N0 3 + CO -> N0 2 + CO 2 ~"0303{fast) 

289 www.cki2.0rg 



The first collision in this reaction occurs between two NO2 molecules and produces an NO3 
molecule and an NO molecule. The second collision in the mechanism occurs between the 
NO3 molecule produced in step 1 and a CO molecule producing an NO2 and a CO2. When 
all the steps in the reaction mechanism are added, the NO3 (on both sides) cancel and 
NO3 does not appear in the net reaction. The NO2 in the product cancels one of the NO2 
molecules in the reactant and the net reaction is CO + NO2 — ► CO2 + NO. The overall 
reaction rate for this reaction (and all reactions) will be exactly the same as the reaction 
rate for the slowest step. The rate law for the slowest step is R = k[N02] 2 and therefore, 
the rate law for the net reaction is the same, even though two NO2 molecules do not appear 
in the reactants for the net reaction. That is why the rate law for the net reaction must be 
determined experimentally. 

Some chemical reactions may occur with a single collision between reactant particles. The 
possibility of a single collision reaction is limited to reactions involving two particles or in 
some cases, three particles. The probability of three particles arriving at the same point at 
the same time for a single three-particle collision is low. Collisions involving more than three 
particles essentially never occur. 

Suppose the reaction between carbon and oxygen to yield carbon dioxide occurred with a 
single collision between a carbon atom and an oxygen molecule. 

C + 2 -► C0 2 

In such a case, the reaction mechanism and the net reaction are the same reaction. The net 
reaction represents the reaction mechanism and the slowest step in the reaction mechanism. 
Therefore, for this very simple reaction, the rate law may be written by looking at the net 
reaction; Rate = k[C][02]. 

If a three particle reaction occurred in a single collision, the rate law could also be written 
from the net reaction. 

2 NO (g) + 2(g) - 2 N0 2(g) 
Rate = k[NO] 2 [0 2 ] 

This reaction and the rate law could also be written in the following manner, 

NO (g) + NO (g) + 2{g) - 2 N0 2(g) 
Rate = k[NO][NO][0 2 ] 

and that's why the coefficients of the reactants become exponents in the rate law. 

The great majority of reactions that involve more than two particles as reactants occur by 
a series of collisions (reaction mechanism) and for these reactions, the rate law must be 
determined experimentally. 

www.ckl2.org 290 



Consider the following set of experimental data from which the rate law may be determined 
for the reaction between NO and O2. 

Table 23.1: 

Trial Initial [NO] Initial [0 2 ] Experimentally 

Determined Rate 

1 0.10 M 0.10 M 1.2xlO" 8 M/s 

2 0.10 M 0.20 M 2.4 x 10" 8 M/s 

3 0.30 M 0.10 M 1.08 x 10" 7 M/s 



We pick two trials in which one of the reactant concentrations is held constant and the other 
reactant concentration changes. To begin, we choose trials 1 and 2 in which the concentration 
of NO is constant and the concentration of O2 changes. We can determine the order of the 
reaction with respect to O2 with the following mathematics. 

(multiple of O2 concentration) x = (multiple of rate), where the exponent, x, is the order of 
the reaction with respect to O2. 

The concentration of O2 has been doubled and the rate has been doubled, so 

2 X = 2 and therefore, x = 1. The order of the reaction with respect to oxygen is 1. 

We now choose two trials in which the O2 concentration is held constant and the concentra- 
tion of NO varies. In trials 1 and 3, the concentration of NO has been tripled and the rate 
has been increased by a factor of 9. 

3 X = 9, hence x = 2. The order of the reaction with respect to NO is 2. Now, we can write 

the rate law. 
Rate = k[NO] 2 [0 2 ] 

We can determine the value of k by choosing any one of the trials and substituting the known 
values for the concentrations and rate. Inserting the values from trial 1 into the rate law 
yields 

1.2 x 10" 8 M/s = k(0.10) 2 (0.10), and solving for k yields 
k = 1.2 x 10" 5 M-V 1 . 

Thus, the rate law for this reaction is: 

291 www.ckl2.org 



Rate = (1.2 x 10" 5 M-V^NO] 2 ^]. 

As long as the reaction occurs at the temperature for which this rate law was determined, 
the rate can be determined by plugging in the initial concentrations of the reactants. The 
value of k changes with temperature, so this k value is only true at the specific temperature 
for which the data was determined. 

In a number of reactions, the order of the reaction for a particular reactant will be determined 
to be zero. This indicates that the reaction rate does not depend on the concentration of 
that reactant and the reactant will not appear in the rate law. (Anything raised to the power 
of equals 1.) 

Consider the following reaction and experimental data. 

A + B + C -> products 









Table 23.2: 








Trial 


Initial 


[A] 


Initial 


[B] 


Initial 


[C] 


Rate 


1 
2 
3 
4 


1.0 M 
1.0 M 
1.0 M 
2.0 M 




1.0 M 
1.0 M 
2.0 M 
2.0 M 




1.0 M 
2.0 M 
1.0 M 
1.0 M 




0.40 M/s 
0.40 M/s 
1.6 M/s 
1.6 M/s 



The reaction rate will be related to the equation R = k[A] a [B] b [C] c 

Comparing trials 1 and 2, we have [A] and [B] remaining constant while [C] is doubled. The 
rate also remains the same. 

(multiple of C concentration) = (multiple of rate) 

2 C = 1, so the exponent, c, must equal anything to the power of zero equals 1. 

Comparing trials 3 and 4, we have [B] and [C] remaining constant while [A] is doubled. The 
rate remains the same. 

(multiple of A concentration) a = (multiple of rate) 

2 a = 1, so the exponent, a, must equal anything to the power of zero equals 1. 

Comparing trials 1 and 3, we have [A] and [C] remaining constant while [B] is doubled. The 
rate increases by a factor of 4. 

(multiple of B concentration) b = (multiple of rate) 
www.ckl2.org 292 



2 b = 4, so the exponent, b, must equal 2. 
Therefore, the rate expression will be: 

Rate = k[A]°[B] 2 [C]° = k[B] 2 . 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chemical Kinetics. 
60 Minute Class Periods per Lesson 

Table 23.3: 

Lesson Number of Class Periods 

23.1 Rate of Reactions 1.5 

23.2 Collision Theory 1.0 

23.3 Potential Energy Diagrams 1.0 

23.4 Factors That Affect Reaction Rates 2.0 

23.5 Reaction Mechanisms 1.0 

Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chemical Kinetics. 

Chemical Kinetics Materials List 

Table 23.4: 

Lesson Strategy or Activity Materials Needed 

23.1 
23.2 
23.3 
23.4 
23.5 



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Multimedia Resources 
Possible Misconceptions 

Identify: 

Many students assume that all chemical changes are irreversible. 

Clarify: 

A reaction that proceeds in only one direction is known as an irreversible reaction. A 
chemical reaction in which the product (s) can react to produce the original reactant(s) is a 
reversible reaction. For example, the reaction of calcium oxide (CaO) with carbon dioxide 
(CO2) produces calcium carbonate (CaCOs). If the calcium carbonate is heated, the reaction 
produces calcium oxide and carbon dioxide - the original reactants. 

Promote Understanding: 

Place about 10 mL of concentrated nitric acid in a beaker. Add a penny. Pour the red gas 
(NO2) that results into a test tube and stopper it. Place the test tube into an ice bath. The 
gas (N2O4) will become almost colorless. Return the test tube to room temperature. The 
gas (NO2) will return to its red color. 

Discuss: 

Write the equation: 2 NC>2(g) ^=f ^O^g) on the board. Inform students that the substance 
on the left side of the arrow is the reactant and the substance on the right side of the arrow 
is the product of the chemical reaction. 

Ask: 

"How do you know that a chemical reaction took place? (A new substance was formed.) 

Ask: 

How do you know that the reaction is reversible? (The product was able to re-form the 
original reactant.) 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chemical Kinetics 



www.ckl2.org 294 



Table 23.5: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



23.1 8a 

23.2 8b, 8d 

23.3 7b, 8d 

23.4 8b, 8c, 8d 

23.5 8d 



23.3 Lesson 23.1 Rate of Reactions 
Key Concepts 

In this lesson students explore the rates of chemical reactions. 

Lesson Objectives 

• Define chemical kinetics and rates of reactions. 

• Write the rate expression and the units for the rate expression. 

• Define instantaneous rate. 

• Calculate instantaneous rate using a tangent line. 

Lesson Vocabulary 

chemical kinetics The study of rates of chemical reactions and how factors affect rates 
of reactions. 

rate of reaction The measure at which the products are formed over a time interval or 
the rate at which the reactants are consumed over a time interval. 

instantaneous rate The rate of change at a particular time interval. 

Strategies to Engage 

• Give examples of fast (striking a match), slow (production of coal), and moderate 
(food spoilage) chemical reactions. Facilitate a discussion where students list factors 
that affect how fast reactions occur. 

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Strategies to Explore 

Strategies to Extend and Evaluate 

• Have each student record the four sentences in this section that most clearly represent 
the main ideas. Read key sentences in the text and have students raise their hands 
if they have recorded that sentence. Facilitate a discussion in which students defend 
their selections. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 23.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



23.4 Lesson 23.2 Collision Theory 
Key Concepts 

In this lesson students explore reactions rates in terms of collisions between reacting particles. 

Lesson Objectives 

• Define the collision theory. 

• Describe the conditions for successful collisions. 

• Explain how the kinetic molecular theory applies to the collision theory. 

• Describe the rate in terms of the conditions of successful collisions. 



Lesson Vocabulary 

collision theory Explains why reactions occur at this particle level between atoms, ions, 
and/or molecules. More importantly from the collision theory, is the ability to predict 
what conditions are necessary for a successful reaction to take place. 



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kinetic molecular theory Provides the foundation for the collision theory on the atomic 
level. The collisions between particles are considered to elastic in nature. 

threshold energy The minimum amount of energy necessary for a reaction to take place. 

collision frequency The total number of collisions per second. 

Strategies to Engage 

• Begin the lesson by reviewing the kinetic molecular theory with students. 

Strategies to Explore 

• Have students write a paragraph explaining Figure 1 that includes using this lesson's 
vocabulary terms. 

Strategies to Extend and Evaluate 

• Have students create a concept map relating the terms and objectives of the concepts 
explored so far in this chapter. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 23.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



23.5 Lesson 23.3 Potential Energy Diagrams 
Key Concepts 

In this lesson students learn what information is contained in potential energy diagrams for 
endothermic and exothermic reactions, how to read them, and how to draw them. 



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Lesson Objectives 

• Define enthalpy, activation energy, activated complex. 

• Describe and draw the difference between endothermic and exothermic potential energy 
diagrams. 

• Draw and label the parts of a potential energy diagram. 

Lesson Vocabulary 

potential energy diagrams Potential energy diagrams in the study of kinetics show how 
the potential energy changes during reactions from reactants to products. 

potential energy The potential energy measures the energy stored within the bonds of 
the reactants and products, and therefore is the internal energy. 

exothermic reactions Reactions that have a potential energy difference between the 
products and reactants that is negative. 

endothermic reactions Reactions that have a potential energy difference between the 
products and reactants that is positive. 

activation energy The minimum amount of energy that needs to be supplied to the sys- 
tem so that a reaction can occur. 

activated complex A high energy transitional state between the reactants and products. 

Strategies to Engage 
Strategies to Explore 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space in 
between. As you explore the lesson, have students write the "answer" to each objective. 

Strategies to Extend and Evaluate 

• Have students play a review game called "Two Truths and a Lie" using what they know 
about potential energy diagrams. To do this, pair students, and have each pair write 
three statements, two of which are facts about potential energy diagrams, and one of 
which is a plausible "lie." Then have each pair join with two other pairs to share what 
they wrote, and try to guess which of the statements are "lies" and which are "truths." 

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Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 23.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

23.6 Lesson 23.4 Factors That Affect Reaction Rates 
Key Concepts 

In this lesson students explore the effect of temperature, surface area, concentration, and 
catalysts on the rate of a chemical reaction. 



Lesson Objectives 

State how the rate of reaction changes as a function of temperature. 

Explain how increased temperature increases the number of particles that can overcome 

the energy barrier. 

Describe the effect of increasing the concentration on the rate of a reaction. 

Indicate which reactants in a multi-step process can affect the rate of a reaction. 

Calculate, using experimental data, the relationship between the ratio of the change 

in concentration of reactants, and ratio of the change in rate. 

Describe the surface area to volume ratio. 

Describe the effect of surface area on reaction rate. 

Describe how the change in the surface area affects the collision frequency. 

Describe real world examples of the effect of surface area on reaction rate. 

Define a catalyst. 

Identify a catalyst in a single equation. 

Identify a catalyst in a multi-step process. 

Describe how a catalyst affects the potential energy diagram. 

Explain how a catalyst affects the rate of the reaction. 

Explain how a catalyst affects our everyday lives, particularly with vitamins. 

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Lesson Vocabulary 

effective collision A collision that results in a reaction. 

multi-step process Reactions that take more than one step in order to make the products. 

surface area to volume ratio The comparison of the volume inside a solid to the area 
exposed on the surface. 

catalyst A substance that speeds up the rate of the reaction without itself being consumed 
by the reaction. 

Strategies to Engage 
Strategies to Explore 

This lesson includes a description of the factors that affect reaction rates. Before reading, 
prepare less proficient readers by having students write the following on the top of separate 
sheets of notebook paper: 

• The Nature of the Reactants 

• Temperature 

• Concentration 

• Surface Area 

• Catalyst 

As they read each section, have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

Strategies to Extend and Evaluate 

• Have students bring in real- world examples of the effect of temperature, surface area, 
concentration, and catalysts on the rate of chemical reactions. Students should be 
prepared to discuss their findings with the class. 

Lesson Worksheets 

There are no worksheets for this lesson. 
www.ckl2.org 300 



Review Questions 

Lesson 4 contains four sub-lessons and each sub-lesson has a set of review questions. Have 
the students answer the Review Questions for each sub-lesson as you cover the sub-lesson. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



23.7 Lesson 23.5 Reaction Mechanism 
Key Concepts 

In this lesson students explore multi-step processes as well as the individual reactions in the 
multi-step process. 



Lesson Objectives 

• Define reaction mechanisms. 

• Identify the rate-determining step. 

• Draw a potential energy diagram for a multi-step process. 



Lesson Vocabulary 



elementary step A single, simple step in a multi-step process involving one or two parti- 
cles. 



reaction mechanism Most reactions do not take place in one step but rather occur as a 
combination of two or more elementary steps. 



rate-determining step The slowest step in the reaction mechanism. 



Strategies to Engage 

• Preview the lesson vocabulary to find out what your students already know about the 
concepts to be explored in this lesson. Have students define each vocabulary term. At 
the end of the lesson encourage students to go back and write the correct definition for 
each incorrect definition. 



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Strategies to Explore 

• Have students write a paragraph explaining Figure 1 that includes using this lesson's 
vocabulary terms. 

Strategies to Extend and Evaluate 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 23.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 23 Assessment 

Provided to teachers upon request at teacher-requests@ckl2.org. 

Chapter 23 Assessment Answers 

Provided to teachers upon request at teacher-requests@ckl2.org. 



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Chapter 24 

TE Chemical Equilibrium 



24.1 Chapter 24 Chemical Equilibrium 
Outline 

This chapter Chemical Equilibrium consists of four lessons that cover relationships between 
forward and reverse reaction rates, the concept of chemical equilibrium, the mathematics of 
the equilibrium constant, Le Chatelier's principle, and solubility product constant calcula- 
tions. 



Lesson 24.1 Introduction to Equilibrium 

Lesson 24.2 Equilibrium Constant 

Lesson 24.3 The Effect of Applying Stress to Reactions at Equilibrium 

Lesson 24.4 Slightly Soluble Salts 



Overview 

In these lessons, students will explore: 



The conditions of chemical equilibrium. 
Equilibrium constant expressions. 
Le Chatelier's Principle. 
Solubility product constant expressions. 



303 www.ckl2.org 



Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Chemical Equilibrium 

In principle, any reaction that can be represented by a balanced chemical equation can take 
place. There are, however, two situations which may inhibit the reaction from occurring. 

• The thermodynamic tendency (the combination of entropy and enthalpy) for the re- 
action to occur may be so small that the quantity of products is very low, or even 
negligible. This type of chemical reaction is said to be thermodynamically inhib- 
ited. 

• The rate at which the reaction proceeds may be so slow that many years are required to 
detect any product at all, in which case we say the reaction is kinetically inhibited. 

As a reaction proceeds, the quantities of the components on one side of the reaction equa- 
tion will decrease and those on the other side will increase. As the concentrations of the 
components on one side of the equation decrease, that reaction rate slows down. As the 
concentrations of the components on the other side of the equation increase, that reaction 
rate speeds up. Eventually the two reaction rates become equal and the composition of the 
system stops changing. At this point, the reaction is in it's equilibrium state and no further 
change in composition will occur, as long as the system is left undisturbed. 

In many reactions, the equilibrium state occurs when significant amounts of both reactants 
and products are present. Such a reaction is said to be reversible. The equilibrium composi- 
tion is independent of the direction from which it is approached. The labeling of substances 
as reactants and products is entirely a matter of convenience. 

The law of mass action states that any chemical change is a competition between a 
forward reaction (left-to-right) and a reverse reaction (right-to- left). The rates of these two 
reactions are governed by the concentrations of the substances reacting, and the temperature. 
As the reaction proceeds, these two reaction rates approach each other in magnitude and at 
equilibrium, they become equal. 

Since the reactions continue at equilibrium (at equal rates), equilibrium is referred to as dy- 
namic equilibrium. At equilibrium, microscopic changes (the forward and reverse reactions) 
continue but macroscopic changes (changes in quantities of substances) cease. 

When a chemical system is at equilibrium, any disturbance of the system, such as a change 
in temperature, or the addition or removal of a reactant or product, will cause the equilib- 
rium to shift to a new equilibrium state (different quantities of reaction components). The 
disturbance in the system causes changes in the reaction rates and quantities of components 

www.ckl2.org 304 



change until the reaction rates again become identical, and a new equilibrium position is 
established. 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chemical Equi- 
librium. 

60 Minute Class Periods per Lesson 

Table 24.1: 

Lesson Number of Class Periods 

24.1 Introduction to Equilibrium 1.0 

24.2 Equilibrium Constant 1.5 

24.3 The Effect of Applying Stress to Reac- 2.0 
tions at Equilibrium 

24.4 Slightly Soluble Salts 1.5 

Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chemical Equilibrium. 

Chemical Equilibrium Materials List 

Table 24.2: 

Lesson Strategy or Activity Materials Needed 

24.1 
24.2 
24.3 

24.4 
24.5 



305 www.ckl2.org 



Multimedia Resources 

You may find these additional web based resources helpful when teaching Chemical Equilib- 
rium: 

• Le Chatelier's Principle Movie: http://genchemist.wordpress.com/2007/10/05/ 
le-chateliers-principle-the-movie/ 

• Le Chatelier's Principle and the Haber Process video clip: http : //videos . howstuff works 
com/hsw/ 12468- chemistry- connect ions- le- chat el ier-and-haber-bosch- video . 
htm 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chemical Equilibrium 

Table 24.3: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

24.1 9b 

24.2 9c 

24.3 9a 
24.4 



24.2 Lesson 24.1 Introduction to Equilibrium 
Key Concepts 

In this lesson students explore the conditions of chemical equilibrium. 
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Lesson Objectives 

• Describe the three possibilities that exist when reactants come together. 

• Identify the three possibilities by looking at a chemical equation. 

• Describe what is occurring in a system at equilibrium. 

• Define dynamic equilibrium. 

• Define the conditions of dynamic equilibrium. 



Lesson Vocabulary 

chemical equilibrium A state that occurs when the rate of forward reaction is equal to 
the rate of the reverse reaction. 



dynamic equilibrium A state that continues in which the rate of the forward reaction 
is equal to the rate of the reverse reaction; or, the number of particles/molecules of 
the reactant becoming the product is equal to the number of particle/molecules of the 
product becoming the reactant. 



Strategies to Engage 

• Explain to students that chemical reactions do not always go completely to products, 
and that in this lesson, they will explore the three possibilities that exist when reactants 
come together. 



Explain to students that in this lesson, they will explore the concept of dynamic equi- 
librium. Give students the opportunity to define this term just by examining the words 
themselves. At the end of the lesson, have students check their original definition and 
make corrections, if necessary. 



Strategies to Explore 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space in 
between. As you explore the lesson, have students write the "answer" to each objective. 



Challenge groups of students to create and perform a short skit to demonstrate chemical 
equilibrium. 



307 www.ckl2.org 



Strategies to Extend and Evaluate 

• As a review of lesson concepts, make a copy of Figure 1 . Below it, rewrite the paragraph 
explaining Figure 1 deleting key words and create an overhead. Have students choose 
words to fill in these blanks so that the text makes sense. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

There are two sub-lessons in lesson 24.1 that each have a set of review questions. Have the 
students answer the review questions for each sub-lesson as you cover it. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



24.3 Lesson 24.2 Equilibrium Constant 
Key Concepts 

In this lesson students explore equilibrium constant expressions. 

Lesson Objectives 

• Write equilibrium constant expressions. 

• Use equilibrium constant expressions to solve for unknown concentrations. 

• Use known concentrations to solve for the equilibrium constants. 

• Explain what the value of K means in terms of relative concentrations of reactants and 
products. 

Lesson Vocabulary 

equilibrium constant (K) A mathematical ratio that shows the concentrations of the 
products divided by concentration of the reactants. 

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Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• As a review of lesson content, have students write questions derived from Bloom's 
Taxonomy. Instruct students to research Bloom's Taxonomy and write and answer one 
question from each of the six levels: knowledge, comprehension, application, analysis, 
synthesis, and evaluation. 

Review Questions 

Have students answer the Lesson 24.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



24.4 Lesson 24.3 The Effect of Applying Stress to Re- 
actions at Equilibrium 

Key Concepts 

In this lesson students explore Le Chatelier's Principle. 

Lesson Objectives 

• State Le Chatelier's Principle. 

• Demonstrate on specified chemical reactions how Le Chatelier's Principle is applied to 
equilibrium systems. 

• Describe the effect of concentration on an equilibrium system. 

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Demonstrate with specific equations how Le Chatelier's Principle explains the effect of 

concentration. 

Describe the effect of pressure as a stress on the equilibrium position. 

Describe the pressure effect in Le Chatelier's Principle. 

Describe the effect of temperature as a stress on an equilibrium system. 

Explain how Le Chatelier's principle explains the effect of temperature. 

Explain how a catalyst works in equilibrium reactions. 

Explain the effect of a catalyst in equilibrium positions. 

Lesson Vocabulary 

Le Chatelier's Principle Applying a stress to an equilibrium system causes the equilib- 
rium position to shift to offset that stress and regain equilibrium. 

The Haber Process A commercial method that makes the maximum amount of ammonia 
using the Le Chatelier's Principle. 

exothermic reaction A reaction in which the heat content of the reactants is greater than 
the heat content of the products. The excess energy is given off as a product. 

endothermic reaction A reaction in which the heat content of the reactants is less than 
the heat content of the products. Energy is needed to be added to the reactants in 
order to form the products. 

catalyst A substance that increases the rate of a chemical reaction but is, itself, left un- 
changed, at the end of the reaction. 

Strategies to Engage 

• Before beginning this lesson, review with students reversible reactions and the concept 
of chemical equilibrium. 

Strategies to Explore 

This lesson includes a description of the effects of applying stress to reactions at equilibrium. 
Before reading, prepare less proficient readers by having students write the following on the 
top of separate sheets of notebook paper: 

• Effect of Concentration Changes 
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• Effect of Pressure Changes 

• Effect of Temperature Changes 

• Effect of a Catalyst 

As they read each section have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

Strategies to Extend and Evaluate 

• Have interested students research practical application of the Le Chatelier's Principle 
such as the Contact Process, cola drinks, and carbon monoxide poisoning. Students 
should be prepared to share their findings with their classmates. 



Review Questions 

Lesson 24.3 has four sub-lessons and each sub-lesson has its own set of Review Questions. 
Have the students answer the Review Questions for each sub- lesson as you cover it. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



24.5 Lesson 24.4 Slightly Soluble Salts 
Key Concepts 

In this lesson students explore solubility product constant expressions. 

Lesson Objectives 

• Define solubility product constants. 

• Write solubility product constant expressions. 

• Calculate solubility product constants. 

Lesson Vocabulary 

solubility product constant, K sp Equilibrium constant for a slightly soluble salt. 

311 www.ckl2.ore 



Strategies to Engage 

• Before beginning this lesson, review with students equilibrium constants. Explain to 
students that in this lesson, they will explore equilibrium constants for slightly soluble 
salts. 

Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

Review Questions 

Have students answer the Lesson 24.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 24 Assessment 

Provided to teachers upon request at teacher-requests@ckl2.org. 

Chapter 24 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



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Chapter 25 



TE Acids and Bases 



25.1 Unit 9 Chemistry of Acids and Bases 
Outline 

This unit, Chemistry of Acids and Bases, includes two chapters that explore properties and 
reactions of acids, bases, salts, water, and buffers. 



• Chapter 25 Acids and Bases 

• Chapter 26 Water, pH, and Titration 



Overview 

Acids and Bases 

This chapter includes the definitions of acids and bases, the causes of strong and weak acids 
and bases, the hydrolysis of salts, and an introduction to pH. 

Water, pH, and Titration 

This chapter covers the mathematics of the dissociation of water, acid-base indicators, acid- 
base titration, and buffers. 

313 www.ckl2.org 



25.2 Chapter 25 Acids and Bases 
Outline 

This chapter Acids and Bases consists of eight lessons that includes the definitions of acids 
and bases, the causes of strong and weak acids and bases, the hydrolysis of salts, and an 
introduction to pH. 

Lesson 25.1 Arrhenius Acids 

Lesson 25.2 Strong and Weak Acids 

Lesson 25.3 Arrhenius Bases 

Lesson 25.4 Salts 

Lesson 25.5 pH 

Lesson 25.6 Weak Acid/Base Equilibria 

Lesson 25.7 Bronsted-Lowry Acids and Bases 

Lesson 25.8 Lewis Acids and Bases 

Overview 

In these lessons, students will explore: 

The Arrhenius acid definition and properties of acids. 

Strong and weak acids in terms of ionization percent. 

The Arrhenius base definition and properties of bases. 

Acid-base neutralization reactions. 

[H+] and [0H-] and pH. 

Weak acids and weak bases as equilibrium systems. 

The Bronsted-Lowry definitions of acids and bases, and acid-base conjugate pairs. 

The Lewis definitions of acids and bases, and reactions of Lewis acids and bases. 



Science Background Information 

The pH at which an Indicator Changes Color 

Many acid-base indicators exhibit exactly three colors. There is the color of the indicator 
when it is predominantly in its molecular form, the color of the indicator when it is predom- 
inantly in its ionic form, and there is the color of the indicator when it is close to 50% in 
each form. Consider a fictitious indicator, HIn, whose Ka is 1.0 x 10" 5 . At pH values below 
5, this indicator is distinctly red, at pH values above 5, it is distinctly yellow, and exactly 
at a pH of 5, the indicator is orange. 



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1 — 


1 \ 




i \ 


J 




\J 



w 



\J 



pH = 2 pH = 3 pH = 4 pH = 5 pH = 6 



pH = 7 pH = 8 



The dissociation equation for the indicator, HIn, is 



HIn 



(aq) 



H+ + In- 



Red Yellow 



When the hydrogen ion concentration is high, the equilibrium is shifted toward the reactants, 
most of the indicator particles are in the form of undissociated molecules, and the solution 
is red. When the hydrogen ion concentration is low, the equilibrium is shifted toward the 
products, most of the indicator particles are in the form of anions, and the solution is yellow. 
At some exact pH, the equilibrium will be adjusted so that exactly 50% of the indicator 
particles are in the form of undissociated molecules, and 50% in the form of anions. In this 
case, the solution will be a mixture of equal numbers of red molecules and yellow ions, hence 
will be orange. 

Here is the equilibrium constant expression for the indicator. 

[H + ] [In" ] 5 

K a = — = 1.0 x 10" 3 

[HIn] 

For the pH at which the color changes, we are seeking the point where half of the indicator 
particles are in each form; in other words, [In-] = [HIn]. When these two values are exactly 
equal, they will cancel from the expression. 



315 



www.ckl2.org 



K„ = 



GOT 



= 1.0x10 



As you can see, mathematically, the [H + ] for this exact point will be equal to the K a value 
and pH = - log (1.0 x 10" 5 ) = 5, which is in agreement with the pictures of the indicator 
colors at various pH's. 

Consider the indicator thymol blue. The undissociated molecules of thymol blue are yellow 
and the anions are blue. The K a for thymol blue is 1.0 x 10" 9 . When this indicator is 50% 
in the form of undissociated molecules and 50% anions, the 50-50 mixture of yellow and 
blue would result in a green color. Calculations of the same type as shown for the previous 
example indicate that the green color will be present when the [H + ] is equal to the value of 
the K a , 1.0 x 10" 9 . Therefore, the color change pH for thymol blue is pH = 9. When the pH 
value is less than 9, the indicator will be yellow, at exactly 9, it will be green, and above 9, 
it will be blue. 

It should be clear that putting a few drops of thymol blue in a solution and getting a resultant 
yellow color does not tell you the pH of the solution. It only tells you that the pH is less than 
9. Similarly, a resulting blue solution of thymol blue only tells you that the pH is greater 
than 9. There is only one color of a thymol blue solution that tells you the pH and that is 
green. 



\ i \ V ^ ? ^ 7 ^ 



V ~~ ? % ? 



\J \J \J w 

pH = 6 pH = 7 P H=8 pH = 9 



w \-j \y 

pH=10 P H=11 pH=12 



www.ckl2.org 



316 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Acids and Bases. 
60 Minute Class Periods per Lesson 

Table 25.1: 



Lesson 



Number of Class Periods 



25.1 Arrhenius Acids 1.0 

25.2 Strong and Weak Acids 1.0 

25.3 Arrhenius Bases 1.0 

25.4 Salts 1.0 

25.5 pH 1.5 

25.6 Weak Acid/Base Equilibria 2.0 

25.7 Bronsted-Lowry Acids and Bases 1.0 

25.8 Lewis Acids and Bases 1.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Acids and Bases. 



Acids and Bases Materials List 



Table 25.2: 



Lesson 



Strategy or Activity 



Materials Needed 



25.1 
25.2 
25.3 
25.4 
25.5 
25.6 
25.7 
25.8 



317 



www.ckl2.org 



Multimedia Resources 

You may find these additional web based resources helpful when teaching Acids and Bases: 

• Interactive pH lab: http://www.proteacher . com/cgi-bin/outsidesite. cgi?id=5268&# 
38;external=http : //www.miamisci . org/ph/guide . html& original=http: //www. 
proteacher. com/110052. shtml&title=The°/„20pH°/„20Factor 

• pH scale activity: http: //www. quia. com/rd/1975.html?AP_rand=201033057 

• Titration demonstration: http: //www. chem. iastate. edu/group/Greenbowe/sections/ 
projectf older /f lashf iles/stoichiometry/acid_base .html 

Possible Misconceptions 

Identify: Students may think that acid-base strength is the same as concentration. 

Clarify: Concentration refers to the number of moles of solute per liter of solution while 
strength refers to the degree to which the substance forms ions in solution. 

Promote Understanding: Use HC1 and HC2H3O2 as examples. Explain to students that 
hydrochloric is a strong acid because in water, nearly all of the HC1 molecules ionize to form 
H + and CI" ions. On the other hand acetic acid is a weak acid because only a small amount 
of HC2H3O2 molecules ionize to form H + and C2H 3 02~ ions. Explain to students that the 
strength of an acid or base depends on its ability to ionize. Also, if a solution has a large 
number of ions in it, it is a strong electrolyte, whereas a solution that has only a few ions 
present is a weak electrolyte. Into three separate beakers add 40 rnL of 1.0 M hydrochloric 
acid, acetic acid, and oxalic acid. Test each solution with a conductivity tester. 

Discuss: Point out to students that each acid had the same concentration (1.0 M) but they 
did not have the same strength. Discuss with students the difference between acid-base 
strength and concentration. 

Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Acids and Bases 



www.ckl2.org 318 



Table 25.3: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



25.1 5a, 5b,5c 

25.2 5c 

25.3 5a, 5b, 5e 

25.4 5a 

25.5 le, 5d, 5f 

25.6 le, 5c 

25.7 5e 

25.8 5e 



25.3 Lesson 25.1 Arrhenius Acids 
Key Concepts 

In this lesson students explore the Arrhenius acid definition and properties of acids. 



Lesson Objectives 

• Define an Arrhenius acid and know some examples of acids. 

• Define operational and conceptual definition. 

• Explain the difference between operational and conceptual definitions. 

• Describe the properties of acids. 

• Describe some of the reactions that acids undergo. 



Lesson Vocabulary 

Arrhenius acid A substance that produces H + ions in solution. 



operational definitions Definitions that describe how something behaves, (i.e. the op- 
erational definition of acids includes tastes sour and turns blue litmus red.) 



conceptual definitions Definitions that describe why something behaves the way it does, 
(i.e. the conceptual definition of acids includes reacting with bases to neutralize them.) 

319 www.ckl2.org 



Strategies to Engage 

• Set up a KWL chart on the board or chart paper. Activate prior knowledge by asking 
students what they Know about acids and bases and write that information in the first 
column. Have students set goals specifying what they Want to learn about acids and 
bases and write this information in the second column. At the end of the chapter, have 
students discuss what they Learned about acids and bases and write this information 
in the third column. 



Facilitate a discussion with students about how acids and bases affect our everyday 
lives. Have students list substances they think contain either acids or bases. Ask 
students what properties helped them to identify the substances as either acids or 
bases. Have students come up with their own operational definitions of acids and 
bases. Use this opportunity to gauge student understanding of acids and bases and to 
clear up any misconceptions. 



Strategies to Explore 

Strategies to Extend and Evaluate 

• As a review of lesson concepts, have each student record the four sentences in this 
section that most clearly represent the main ideas. Read key sentences in the text 
and have students raise their hands if they have recorded that sentence. Facilitate a 
discussion in which students defend their selections. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 25.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



www.ckl2.org 320 



25.4 Lesson 25.2 Strong and Weak Acids 
Key Concepts 

In this lesson students explore strong and weak acids in terms of ionization percent. 

Lesson Objectives 

• Distinguish between strong and weak acids. 

• Identify strong and weak acids from given choices. 

• Describe how strong and weak acids differ in terms of concentrations of electrolytes. 

Lesson Vocabulary 

strong acid Acids that completely ionize or undergo 100% ionization in solution (i.e. 
HCL). 

weak acids Acids that do not completely ionize or undergo 100% ionization in solution 
(i.e. HC 2 H 3 2 ). 

Strategies to Engage 

• Have students read and propose answers to the questions posed in the lesson intro- 
duction. At the end of the lesson have students check their answers, and make the 
necessary corrections. 

Strategies to Explore 

• Have students write a paragraph describing how strong and weak acids differ in terms 
of concentrations of electrolytes. 

Strategies to Extend and Evaluate 

Review Questions 

Have students answer the Lesson 25.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. Answers to these questions are provided to teachers upon request 
at teacher-requests@ckl2.org. 

321 www.ckl2.org 



25.5 Lesson 25.3 Arrhenius Bases 
Key Concepts 

In this lesson students explore the Arrhenius base definition and properties of bases. 



Lesson Objectives 

• Define an Arrhenius base and know some examples of bases. 

• State the properties of bases. 

• Describe the neutralization reaction that bases undergo. 



Lesson Vocabulary 

Arrhenius base A substance that produces OH~ ions in a solution. 

Strategies to Engage 

• Before beginning this lesson, review with students the Arrhenius definition of an acid. 
Have students recall the formula for most bases and see if they can come up with the 
Arrhenius definition of a base. Tell students to "stay tuned' to see if their definition 
was correct. 



Strategies to Explore 

• After exploring how bases affect indicators, have groups of students write the procedure 
to perform a color-change trick using acids, bases, and indicators. After their procedure 
is approved, have the students use their procedure to perform a chemistry magic show. 



Strategies to Extend and Evaluate 

• Have students do library research on the topic of acids and bases in photography and 
prepare a written report, Keynote or PowerPoint slideshow, or display. 



Lesson Worksheets 

There are no worksheets for this lesson. 
www.ckl2.org 322 



Review Questions 

Have students answer the Lesson 25.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. Answers to these questions are provided to teachers upon request 
at teacher-requests@ckl2.org. 



25.6 Lesson 24.4 Salts 
Key Concepts 

In this lesson students explore acid-base neutralization reactions. 



Lesson Objectives 

• Describe the formation of salts in neutralization reactions in terms of Arrhenius theory. 

• Identify acidic, basic, and neutral salts from neutralization reaction. 



Lesson Vocabulary 

basic salt A salt formed in a neutralization reaction between a weak acid and a strong 
base. 



acidic salt A salt formed in a neutralization reaction between a strong acid and a weak 
base. 



neutral salt A salt formed in a neutralization reaction between a strong acid and a strong 
base or a weak acid and a weak base. 



Strategies to Engage 
Strategies to Explore 

• Have students create a flow chart that can be used to determine the type of salt that 
will form from an acid/base neutralization reaction. Encourage interested students to 
show their flow charts to the class and have the class choose the best one. 

323 www.ckl2.org 



Strategies to Extend and Evaluate 

• Have students work in pairs or teams to write a poem about acids, bases, and salts. 
Their poems should explain what they are, some of their properties, and how they 
differ from each other. 



• Have students do library research on the topic of natural solutions to acid rain and 
prepare a written report, Keynote or PowerPoint slideshow, or display. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 24.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



25.7 Lesson 25.5 pH 
Key Concepts 

In this lesson students explore [H + ] and [OH - ] and pH. 



Lesson Objectives 

• Calculate [H + ] for strong acids and [OH - ] for strong bases. 

• Define autoionization and use it to find [H + ] from [OH - ] or to find [OH - ] from [H~ 

• Describe the pH scale. 

• Define pH. 

• Calculate pH from [H + ] or vice versa. 



Lesson Vocabulary 

pH scale A scale measuring the [H + ] with values from to 14. 
www.ckl2.org 324 



pH = —log [H + ] - Formula used to calculate the power of the hydronium ion. 
autoionization When the same reactant acts as both the acid and the base. 



ion product constant for water K w , is the product of the hydronium ion and the hy- 
droxide ion concentrations in the autoionization of water. 



Strategies to Engage 

• Students are likely to have heard about pH in advertising and popular media (e.g., 
shampoos, antacids). Call on volunteers to share with the class anything they already 
know about pH. Point out correct responses and clear up any misconceptions. Tell 
students they will learn more pH in this lesson. 

Strategies to Explore 

• Review acidic, basic, and neutral salts. Use a pH meter to demonstrate pH of salts of 
weak acids and bases. 



Strategies to Extend and Evaluate 

• Ask students to come up with their own lesson review questions. Then have them 
exchange papers with a classmate to have students answer each others questions. 



Have students write a paragraph about a person preparing meals in a restaurant. In 
their paragraphs, ask them to describe various solutions as acids or bases, and estimate 
the pH values. 

Encourage interested students to do library research on Soren Sorensen and the concept 
of pH. Students should be prepared to share their findings with the class. 

Encourage interested students to do library research on the topic of pH and home food 
canning. Students should be prepared to share their findings with the class. 



Have groups of students research and prepare natural acid-base indicators such as those 
that can be made from cabbage juice, cherries and tumeric. Students should do an 
in-class demonstration of their chosen indicator. 

325 www.ckl2.org 



Review Questions 

Have students answer the Lesson 25.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



25.8 Lesson 25.6 Weak Acid/Base Equilibria 
Key Concepts 

In this lesson students explore weak acids and weak bases as equilibrium systems. 

Lesson Objectives 

• Define weak acids and weak bases in terms of equilibrium. 

• Define K a and Kb- 

• Use K a and Kb to determine acid and base strength. 

• Use K a and Kb in acid/base equilibrium problems. 

Lesson Vocabulary 

acid ionization constant K a represents the equilibrium constant for the ionization of a 
weak acid. 



base dissociation constant Kf, represents the equilibrium constant for the dissociation 
of a weak base. 



Strategies to Engage 

• Before beginning this lesson, review with students equilibrium constants. Explain to 
students that in this lesson, they will explore equilibrium constants for acids and bases. 
Give students the opportunity to define the vocabulary terms just by examining the 
words themselves. At the end of the lesson, have students check their original definition 
and make corrections, if necessary. 



www.ckl2.org 326 



Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

• On the board or chart paper, have students write a class summary of this lesson. Have 
one student come up with the first sentence, and have students contribute sentences 
until the entire lesson has been summarized. 



Lesson Worksheets 

Copy and distribute the worksheet titled Weak Acids and Bases from the workbook. 



Review Questions 

Have students answer the Lesson 25.6 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



25.9 Lesson 25.7 Bronsted Lowry Acids-Bases 
Key Concepts 

In this lesson students explore the Bronsted- Lowry definitions of acids and bases and acid- 
base conjugate pairs. 

Lesson Objectives 

• Define a Br0nsted-Lowry acid and base. 

• Identify Br0nsted-Lowry acids and bases from balanced chemical equations. 

• Define conjugate acid and conjugate base. 

• Identify conjugate acids-bases in balanced chemical equations. 

• Identify the strength of the conjugate acids and bases from strengths of the acids and 
bases. 



327 www.ckl2.org 



Lesson Vocabulary 

Br0nsted-Lowry acid A substance that donates a proton (H + ). 

Br0nsted-Lowry base A substance that accepts a proton {H + ). 

amphoteric substances Substances that act as both acids and bases in reactions (i.e. 
NH 3 ). 

conjugate acid The substance that results when a base gains (or accepts) a proton. 

conjugate base The substance that results when an acid loses (or donates) a proton. 

Strategies to Engage 

• Review with students the Arrhenius acid/base definitions. Explain to students that in 
this lesson they will explore a more generalized definition. Encourage students to give 
reasons why a more generalized definition was necessary. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• As a review of this lesson, have students record what they think is the main idea of 
each section. Have pairs of students come to a consensus on each main idea. Then, 
have each pair combine with another pair and again come to a consensus. Finally, have 
each group share their results with the class. DI (LPR) 

• Have students create a concept map showing the relationships among the lesson vo- 
cabulary terms. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 25.7 Review Questions that are listed at the end of the 
lesson in their FlexBook. 



www.ckl2.org 328 



Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



25.10 Lesson 25.8 Lewis Acids and Bases 
Key Concepts 

In this lesson students explore the Lewis definitions of acids and bases, and reactions of 
Lewis acids and bases. 

Lesson Objectives 

• Define a Lewis acid and a Lewis base. 

• Define a coordinate covalent bond. 

• Identify a Lewis acid and a base in reactions. 

Lesson Vocabulary 

Lewis acid A substance that accepts a pair of electrons from a substance (i.e. BF3). 

Lewis base A substance that donates a pair of electrons from a substance (i.e. NH 3 ). 

coordinate covalent bond A covalent bond formed where both electrons that are being 
shared come from the same atom. 



Strategies to Engage 

• Have students recall what they know about Gilbert Lewis. They may recall that he 
is the scientist after whom Lewis structures are named. Review Lewis structures with 
students and have students try to figure out what the Lewis acid-base definitions focus 
on. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students use grid paper to make a crossword puzzle using the vocabulary terms. 
Ask students to exchange papers with a classmate and solve each other's puzzles. 



329 www.ckl2.org 



• Have students write a paragraph explaining the three acid-base theories explored in 
this chapter. 

• Ask students to search for examples of bad science about acids and bases on the web 
or in books. Have them quote the claim, reference the source, and then explain what 
is wrong. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 25.8 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 25 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 25 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 330 



Chapter 26 



TE Water, pH and Titration 



26.1 Chapter 26 Water, pH, and Titration 
Outline 

This chapter Water, pH, and Titration consists of four lessons that cover the mathematics 
of the dissociation of water, acid-base indicators, acid-base titration, and buffers. 

• Lesson 26.1 Water Ionizes 

• Lesson 26.2 Indicators 

• Lesson 26.3 Titration 

• Lesson 26.4 Buffers 

Overview 

In these lessons, students will explore: 

• The autoionization of water, and the mathematics of pH and pOH. 

• Natural and synthetic indicators. 

• How the process of titration is used to determine the concentration of acids and bases. 

• The chemistry of buffer solutions. 

Science Background Information 

Acid Rain 

331 www.ckl2.org 



The exceptional characteristics of the substance known as water have been recognized and 
appreciated for millennia. In particular, its ability as a solvent provides for many of the 
vital processes enabling life, such as acting as the medium in which red blood cells transport 
oxygen in our bodies. Yet water's propensity to dissolve ions, other liquids and even gases 
may not always produce physical or biochemical advantages. 

The water supply on Earth is continuously transported and concomitantly purified by a 
mechanism known as the hydrological cycle. As solar radiation heats the Earth's surface, 
water molecules evaporate and then condense into cloud formations as they reach higher 
elevations and cooler atmospheric levels. Large-scale weather patterns transport the water in 
these cloud formations around the globe, and return the water to the surface as precipitation. 
Despite the purification of the substance by this process, rainwater is found to have a pH 
that is not neutral as one might expect, but mildly acidic. During its passage through the 
atmosphere, water's extraordinary capacity as a solvent absorbs carbon dioxide in the air, 
and small quantities of carbonic acid is generated as shown: 



H 2 + C0 2 -► H 2 C0 3 -»■ H+ + HCO 



:-! 



In our modern industrialized world, there are other gases present in the atmosphere that, 
like C0 2 , can dissolve in atmospheric moisture. In particular, the presence of NO x and SO x , 
byproducts of fossil fuel combustion, is a specific concern. 



www.ckl2.org 332 



333 www.ckl2.org 



Table 26.1: (continued) 



NO x , formed by the reac- 
tion of nitrogenous contam- 
inants in fuels with oxygen, 
can react with water in the 
atmosphere to generate ni- 
tric acid, HNO3. In its con- 
centrated form, nitric acid is 
a corrosive material that can 
dissolve some metals. Like- 
wise, sulfur oxide contam- 
inants react with moisture 
yielding sulfuric acid, the 
viscous acid found in lead- 
acid car batteries. As these 
acids are produced and dis- 
persed in the atmosphere, 
they constitute an environ- 
mental issue that transcends 
borders and physical bound- 
aries. 



• * 






Source: http://en. 

wikipedia. org/wiki/ 
File : Pollution_-_ 
Damaged_by_acid_rain. , 
Author: Nino Barbieri, 
License: GNU Free Docu- 
mentation 



ilsffmm zm**^ 



Table 26.1: 



NO x , formed by the reac- 
tion of nitrogenous contam- 
inants in fuels with oxygen, 
can react with water in the 
atmosphere to generate ni- 
tric acid, HNO3. In its con- 
centrated form, nitric acid is 
a corrosive material that can 
dissolve some metals. Like- 
wise, sulfur oxide contam- 
inants react with moisture 
yielding sulfuric acid, the 
viscous acid found in lead- 
acid car batteries. As these 
acids are produced and dis- 
persed in the atmosphere, 
they constitute an environ- 
mental issue that transcends 
borders ,and physical bound- 



www 
aries. 



.org 



Acid rain is then precipi- 
tation that possesses acid- 



334 




Source: http://en. 

wikipedia. org/wiki/ 
File : Pollution_-_ 
Damaged_by_acid_rain. , 
Author: Nino Barbieri, 
License: GNU Free Docu- 
mentation 



Table 26.1: (continued) 



NO x , formed by the reac- 
tion of nitrogenous contam- 
inants in fuels with oxygen, 
can react with water in the 
atmosphere to generate ni- 
tric acid, HNO3. In its con- 
centrated form, nitric acid is 
a corrosive material that can 
dissolve some metals. Like- 
wise, sulfur oxide contam- 
inants react with moisture 
yielding sulfuric acid, the 
viscous acid found in lead- 
acid car batteries. As these 
acids are produced and dis- 
persed in the atmosphere, 
they constitute an environ- 
mental issue that transcends 
borders and physical bound- 
aries. 



• * 






Source: http://en. 

wikipedia. org/wiki/ 
File : Pollution_-_ 
Damaged_by_acid_rain. , 
Author: Nino Barbieri, 
License: GNU Free Docu- 
mentation 



ilsffmm zm**^ 



Pacing the Lessons 



Use the table below as a guide for the time required to teach the lessons of Water, pH, and 
Titration. 



60 Minute Class Periods per Lesson 



Table 26.2: 



Lesson 



Number of Class Periods 



26.1 Water Ionizes 

26.2 Indicators 

26.3 Titration 

26.4 Buffers 



0.5 
1.0 
2.0 
1.5 



335 



www.cki2.0rg 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Water, pH, and Titration. 

Water, pH, and Titration Materials List 

Table 26.3: 

Lesson Strategy or Activity Materials Needed 

26.1 
26.2 
26.3 
26.4 

Multimedia Resources 

You may find these additional internet resources helpful when teaching Water, pH, and 
Titration: 

• Lesson on buffer solutions: http: //www.mhhe . com/physsci/chemistry/essentialchemistry/ 
flash/bufferl2.swf 

• List of household acid-base indicators: http: //antoine .frostburg. edu/chem/senese/ 
101/acidbase/f aq/household- indicators . shtml 

• pH calculation problem generator: http://science.widener.edu/svb/tutorial/ 
phcalcs .html 

• Autoionization of water animation: http : //chemmovies . unl . edu/ChemAnime/AUTOWD/ 
AUTQWD . html 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Water, pH, and Titration' 
www.ckl2.org 336 



Table 26.4: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



26.1 

26.2 5d 

26.3 lb, 5d 

26.4 5g 



26.2 Lesson 26.1 Water Ionizes 
Key Concepts 

In this lesson students explore the autoionization of water and the mathematics of pH and 
pOH. 



Lesson Objectives 

• The students will write the equation for the autoionization of water, and express the 
concentration of hydrogen and hydroxide ion in a neutral solution at 25°C. 
The students will express the value of K w in a water solution at 25°C. 
The students will write the formulas for pH and pOH, and show the relationship 
between these values and K w . 

The students will express the relationship that exists between pH, pOH, and K w . 
Given the value of any one of the following values in a water solution at 25°C, the 
students will calculate all the other values; [H + ], [OH~], pH, and pOH. 
The students will state the range of values for pH that indicate a water solution at 
25°C is acidic. 

The students will state the range of values for pH that indicate a water solution at 
25°C is basic. 

The students will state the range of values for pH that indicate a water solution at 
25°C is neutral. 



Lesson Vocabulary 



autoionization Autoionization is when the same reactant acts as both the acid and the 
base. 



33 7 www.ckl2.org 



Strategies to Engage 

• Review the Bronsted-Lowry definition of acids and bases. Write the formula for water 
on the board in the form of HOH. Have students attempt to use these two concepts to 
write an equation showing the autoionization of water. 



Strategies to Explore 

Strategies to Extend and Evaluate 

• Challenge interested students to come up with their own questions addressing this 
objective; "Given the value of any one of the following values in a water solution 
at 25°C, the student will calculate all the other values; [H + ], [OH~], pH, and pOH". 
Students may then exchange papers with a classmate to have them answer each other's 
questions. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 26.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Teachers |body= 



Answers to Review Questions 
Lesson 1: Water Ionizes 

1. The pH scale is typically a scale from to 14 because most acids and bases fall within 
these values. A pH scale measures the level of H + ions, decreasing as the pH increases. 
The pOH scale measures the level of 0H~ which would also decrease as pOH increases. 
For acids and bases dissolved in water, there is always present some form level of H + 
and 0H~ in the solution. We can then calculate the pH and the pOH for these 
solutions. pH + pOH = 14.0. 



www.ckl2.org 338 



2. Since K w = 1.0 x 10 14 which is a very small number, it means that there are very few 
products and a large number of reactants. 

3. (c) 9.75 

4. (b) 3.47 

5. (a) 5.80 

6. (d) 9.55 x 10" 11 mol/L 

7. (d) 9.4, basic 
8. 

K w = [OH-}[H 3 + ] 
[H 3 + ] = [OH-] 
K w = [H 3 + ] 2 
1.0 x 10" 13 = [H 3 + ] 2 

[H 3 + ] = Vl.O x 10" 13 
[H 3 + ] = 3.16 x 10" 7 mol/L 
[OH~] = 3.16 x 10 -7 mol/L 
pH = -log [H 3 + ] 
pH = -log (3.16 x 10" 7 ) 
pH = 6.50 
pOH = -log [OH~] 
pOH = -log (3.16 x 10" 7 ) 
pOH = 6.50 



26.3 Lesson 26.2 Indicators 
Key Concepts 

In this lesson students explore natural and synthetic indicators. 



Lesson Objectives 

Define an acid-base indicator. 

Explain the difference between natural and synthetic indicators. 

List examples of natural and synthetic indicators. 

Explain how indicators work. 

Explain the usefulness of indicators in the lab. 



339 www.ckl2.org 



Lesson Vocabulary 

indicator A substance that changes color at a specific pH and is used to indicate the pH 
of the solution. 

natural indicator An indicator that is produced from a substance that is naturally oc- 
curring, or is itself a naturally occurring substance. 

synthetic indicator An indicator that is a complicated structure of an organic weak acid 
or base. 

Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 

Strategies to Explore 

• Have students write a short paragraph comparing and contrasting natural and synthetic 
indicators. They should briefly explain the properties for each type of indicator. 

Strategies to Extend and Evaluate 

• Have students work in pairs or teams to write a poem about indicators. Their poems 
should explain what indicators are, how they work, and give some examples of natural 
and synthetic indicators. 

• Outline the main concepts of the lesson as a class. Discuss the main concepts as you 
prepare the outline. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 26.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



www.ckl2.org 340 



Answers to Review Questions: Lesson 2: Indicators 
26.4 Lesson 26.3 Titrations 
Key Concepts 

In this lesson students explore how the process of titration is used to determine the concen- 
tration of acids and bases. 

Lesson Objectives 

Define titrations and identify the different parts of the titration process. 

Explain the difference between the endpoint and the equivalence point. 

Describe the three types of titration curves. 

Identify points on the titration curves for the three types of titrations. 

Define a standard solution. 

Calculate the accurate concentration of an acid or base using a standard. 

Calculate unknown concentrations or volumes of acids or bases at equivalence. 

Lesson Vocabulary 

titration The lab process in which a known concentration of base (or acid) is added to a 
solution of acid (or base) of unknown concentration. 

titrant The solution in the titration of known concentration. 

burette A piece of equipment used in titrations to accurately dispense the volume of the 
solution of known concentration (either a base or an acid). 

Erlenmeyer flask A piece of equipment used in titrations (and other experiments) to hold 
a known volume of the unknown concentration of the other solution (either the acid 
or the base). 

endpoint The point in the titration where the indicator changes color. 

equivalence point The point in the titration where the number of moles of acid equals 
the number of moles of base. 

pH meter A device used to measure the changes in pH as the titration goes from start to 
finish. 

341 www.ckl2.org 



titration curve A graph of the pH versus the volume of titrant added. 

standard solution A solution whose concentration is known exactly and is used to find 
the exact concentration of the titrant. 

Strategies to Engage 

• Review some of the prior knowledge students have obtained about acids and bases, 
about chemical reactions, molarity calculations, and about indicators that apply to 
the concept of titrations. 

Strategies to Explore 

• Challenge interested students to describe the process of titration as concisely and 
correctly as possible. Have the rest of the class choose the student who is able to 
correctly describe the process using the least amount of words. 

Strategies to Extend and Evaluate 

• Have students use grid paper to make a crossword puzzle using the vocabulary terms. 
Ask students to exchange papers with a classmate and solve each other's puzzles. 

• Have students write a one-paragraph summary of this lesson. Instruct students to 
correctly use each vocabulary term in their summary. 

• Have students use titration to test antacids quantitatively. Divide students into groups 
and ask them to do research to find a suitable experimental procedure. After their 
procedures have been approved, allow them to perform their procedures in class. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 26.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

www.ckl2.org 342 



Answers to Review Questions Lesson 3: Titrations 
26.5 Lesson 26.4 Buffers 
Key Concepts 

In this lesson students explore the chemistry of buffer solutions. 

Lesson Objectives 

• Define a buffer and give various examples of buffers. 

• Explain the effect of a strong acid on the pH of a weak acid/conjugate base buffer. 

• Explain the effect of a strong base on the pH of a weak base/ conjugate acid buffer. 

Lesson Vocabulary 

buffer A buffer is a solution of a weak acid and its conjugate base or a weak base and its 
conjugate acid that resists changes in pH when an acid or base is added to it. 

Strategies to Engage 
Strategies to Explore 

• Have students write down the lesson objectives, leaving about 5 or 6 lines of space in 
between. As you explore the lesson, have students write the "answer" to each objective. 

Strategies to Extend and Evaluate 

• Have students work in pairs to create an advertisement for a "buffered" aspirin. It 
should resemble an ad that might appear in a newspaper or a magazine. Students 
should illustrate their ad and write a slogan to explain why the "buffered" aspirin is 
preferred over regular aspirin. 

• Have students write a paper describing how buffers are an application of Le Chatelier's 
Principle. 

• Have students work in pairs or teams to write a poem about buffers. Their poems 
should explain what they are, how they work, and give some examples. 

343 www.ckl2.org 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 26.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Answers to Review Questions for Lesson 4: Buffers 
Chapter 26 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 26 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 344 



Chapter 27 

TE Thermodynamics - HS Chemistry 



27.1 Unit 10 Thermodynamics 
Outline 

This unit, Thermodynamics, includes one chapter that covers the energy involved in bond 
breaking and bond formation, the heat of reaction, the heat of formation, Hess's law, entropy, 
and Gibb's free energy. 

• Chapter 27 Thermodynamics 

Overview 

Thermodynamics 

This chapter covers the energy involved in bond breaking and bond formation, the heat of 
reaction, the heat of formation, Hess's law, entropy, and Gibb's free energy. 

27.2 Chapter 27 Thermodynamics 
Outline 

This chapter Thermodynamics consists of five lessons that cover the energy involved in bond 
breaking and bond formation, the heat of reaction, the heat of formation, Hess's law, entropy, 
and Gibb's free energy. 

• Lesson 27.1 Energy Change in Reactions 

345 www.ckl2.org 



• Lesson 27.2 Enthalpy 

• Lesson 27.3 Spontaneous Processes 

• Lesson 27.4 Entropy 

• Lesson 27.5 Gibb's Free Energy 

Overview 

In these lessons, students will explore: 



Energy changes in endothermic and exothermic reactions. 
Enthalpy and Hess's Law of Heat Summation. 
Spontaneous and non-spontaneous events and reactions. 
The disorder of chemical systems. 
Gibb's Free energy and spontaneity. 



Science Background Information 
Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Thermodynamics. 
60 Minute Class Periods per Lesson 



Table 27.1: 



Lesson 



Number of Class Periods 



27.1 Energy Change in Reactions 

27.2 Enthalpy 

27.3 Spontaneous Processes 
27 A Entropy 

27.5 Gibb's Free Energy 



1.0 
2.0 
1.0 
1.0 

1.5 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Thermodynamics. 

Thermodynamics Materials List 



www.ckl2.org 



346 



Table 27.2: 



Lesson Strategy or Activity Materials Needed 

27.1 
27.2 
27.3 
27.4 
27.5 



Multimedia Resources 

You may find these additional internet resources helpful when teaching Chapter 27: 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Thermodynamics 

Table 27.3: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

27.1 

27.2 7e 

27.3 7b 
27.4 

27.5 7f 



347 www.ckl2.org 



27.3 Lesson 27.1 Energy Change in Reactions 
Key Concepts 

In this lesson students explore energy changes in endothermic and exothermic reactions. 

Lesson Objectives 

• Define energy, potential energy, kinetic energy. 

• Define endothermic and exothermic reactions. 

• Describe how heat is transferred in endothermic and exothermic reactions. 

Lesson Vocabulary 

energy The ability to do work. 

potential energy The energy of position or stored energy. 

kinetic energy The energy of motion. 

enthalpy The amount of energy a system or substance contains. 

heat The energy that is transferred between the system (reactants and products) and the 
surroundings. 

temperature The average kinetic energy of the molecules of a substance. 

Strategies to Engage 

• Have students read the lesson objectives. Facilitate a discussion with students about 
what they already know about the key concepts to be explored in this lesson. Use this 
opportunity to gauge student understanding and address misconceptions. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students work in groups to come up with a way to describe and explain endother- 
mic and exothermic processes to elementary school students. 

www.ckl2.org 348 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Review Questions that are listed at the end of each lesson in their 
FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

27.4 Lesson 27.2 Enthalpy 
Key Concepts 

In this lesson students explore enthalpy and Hess's Law of Heat Summation. 

Lesson Objectives 

Define and understand enthalpy of reaction. 

Calculate the enthalpy of reaction using AH rxn = AH products - AH reactants . 

Describe, interpret, and draw potential energy diagrams. 

Define and understand AHf. 

Define Hess's Law. 

Calculate AH. 

Lesson Vocabulary 

activation energy The minimum amount of energy necessary for a reaction to take place. 

potential energy diagrams Show endothermic chemical reaction; the activation of en- 
ergy and the potential energy of the reactants. 

enthalpy of formation The heat required to form one mole of a substance from its ele- 
ments at standard temperature and pressure. 

Hess's Law If multiple reactions are combined, the enthalpy {AH) of the combined reac- 
tion is equal to the sum of all the individual enthalpies. 

349 www.ckl2.org 



Strategies to Engage 
Strategies to Explore 



Ask students to look at Figure 1 and Figure 2 and write a paragraph to describe the 
illustrations in their own words. 



Strategies to Extend and Evaluate 

Lesson Worksheets 

Copy and distribute the Lesson 27.2 worksheets titled Enthalpy Worksheet and Hess's 
Law Worksheet in the Supplemental Workbook. Ask students to complete the worksheets 
alone or in pairs as a review of lesson content. 



Review Questions 

Have students answer the Lesson 27.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



27.5 Lesson 27.3 Spontaneous Processes 
Key Concepts 

In this lesson students explore spontaneous and non-spontaneous events and reactions. 

Lesson Objectives 

• Define a spontaneous and non-spontaneous reaction. 

• Identify processes as either spontaneous or non-spontaneous. 

• Describe how endothermic and exothermic reactions can be spontaneous or non-spontaneous. 

• Explain the lack of correlation between spontaneity and speed of reaction. 

www.ckl2.org 350 



Lesson Vocabulary 

spontaneous event (or reaction) A change that occurs without outside inference; does 
not relate to rate of a reaction. 



non-spontaneous event (or reaction) A change that will only occur with outside infer- 
ence. 



ionization A special type of dissociation reaction where a molecule ionizes in water to 
produce H-p cations and the anion. Ionization reactions are specific to acids. 



Strategies to Engage 

Strategies to Explore 

Strategies to Extend and Evaluate 

• Have students write a paragraph comparing and contrasting the scientific and everyday 
definitions of spontaneity. 



In order to reinforce the fact that spontaneity does not relate to the speed of a reaction, 
have students research examples of spontaneous reactions that proceed slowly at room 
temperature. Students should be prepared to share their findings with the rest of the 
class. 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 27.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

351 www.ckl2.org 



27.6 Lesson 27.4 Entropy 
Key Concepts 

In this lesson students explore the disorder of chemical systems. 



Lesson Objectives 

• Define entropy. 

• Calculate change in entropy from standard entropies of formation. 

• Relate entropy to the tendency toward spontaneity. 

• Describe the factors that affect the increase or decrease in disorder. 



Lesson Vocabulary 

entropy A measure of the disorder of a system. 

Strategies to Engage 
Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI(LPR) 

Strategies to Extend and Evaluate 

• Have pairs of students create a lesson, using dominoes or cards as visual aids, to explain 
entropy in a way that young children can understand. 

• Have students write a paragraph describing the relationship between entropy and 
changes of state, temperature, and the number of product/reactant particles. 

Lesson Worksheets 

Copy and distribute the Lesson 27.4 worksheet titled Entropy Worksheet in the Supple- 
mental Workbook. Ask students to complete the worksheets alone or in pairs as a review of 
lesson content. 

www.ckl2.org 352 



Review Questions 

Have students answer the Lesson 27.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



27.7 Lesson 27.5 Gibb's Free Energy 
Key Concepts 

In this lesson students explore Gibb's Free energy and spontaneity. 

Lesson Objectives 

• Define Gibbs Free Energy. 

• Calculate Gibbs Free Energy given the enthalpy and entropy. 

• Use Gibbs Free Energy to predict spontaneity. 

Lesson Vocabulary 

Gibbs free energy The maximum energy available to do useful work. 

Strategies to Engage 
Strategies to Explore 

• Have students convert the information in Table 1 into a paragraph that contains the 
information. 

• As a class create a flowchart that can be used to predict spontaneity based on the 
Gibbs free energy equation. 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 
explored in this chapter. DI (ELL) 

• Divide students into groups of three or four to work on problems in this lesson. 

353 www.ckl2.org 



Strategies to Extend and Evaluate 

• Have students create a concept map relating the terms and objectives of the concepts 
explored in this chapter. 

Lesson Worksheets 

Copy and distribute the Lesson 27.5 worksheet titled Enthalpy, Entropy, and Free 

Energy in the Supplemental Workbook. Ask students to complete the worksheets alone or 
in pairs as a review of lesson content. 

Review Questions 

Have students answer the Lesson 27.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 27 Asssessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 27 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



www.ckl2.org 354 



Chapter 28 



TE Electrochemistry 



28.1 Unit 11 Electrochemistry 
Outline 

This unit, Electrochemistry, includes one chapter that covers oxidation-reduction and elec- 
trochemical cells. 

• Chapter 28 Electrochemistry 

Overview 

Electrochemistry This chapter covers oxidation-reduction and electrochemical cells. 

28.2 Chapter 28 Electrochemistry 
Outline 

This chapter Electrochemistry consists of five lessons that cover oxidation-reduction and 
electrochemical cells. 

• Lesson 28.1 Origin of the Term Oxidation 

• Lesson 28.2 Oxidation-Reduction 

• Lesson 28.3 Balancing Redox Equations Using the Oxidation Number Method 

• Lesson 28.4 Electrolysis 

• Lesson 28.5 Galvanic Cells 

355 www.ckl2.org 



Overview 

In these lessons, students will explore: 

• The phlogiston and Lavoisier theories of combustion. 

• Oxidation, reduction, oxidation numbers, and oxidizing and reducing agents. 

• The oxidation number method of balancing redox equations. 

• Electrolysis and electrolysis apparatus. 

• Redox reactions that occur in galvanic cells. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Dependence of Cell Potential on Concentration 

Non-Standard Cells 

For the most part, the discussion of cell potential in high school chemistry deals with cells 
under standard conditions. Standard conditions for cells is 25°C, 1.0 atm pressure, and the 
concentrations of ions is 1.0 M. If you were building a cell to use to do work, you would not 
build a standard cell. Standard cells are used essentially for teaching or experimentation. 
They do not have either the maximum voltage, or the maximum capacity, that can be built 
into Galvanic cells. The advantage of standard cells is that their voltages are precisely 
predictable and easily calculated. 

The cell potential for galvanic cells is closely related to the net movement of materials from 
reactants to products. A faster net reaction would produce a greater cell potential, and a 
slower net reaction would produce a smaller cell potential. At equilibrium, the net reaction is 
zero and therefore, the cell potential would be zero. If the forward reaction rate is increased 
with no change in the reverse reaction rate, then the net forward reaction is greater, and the 
cell potential will be greater. If the reverse reaction rate is decreased with no chain in the 
forward rate, then the net forward reaction is greater, and the cell potential will be greater. 

Consider the cell composed of the standard half cells of aluminum and manganese. 

2 Al {s) + 3 Mnfa -> 2 Alfa + 3Mn {s) E° cell = 0.48 V 

The E° ell for this reaction is determined when the concentrations of manganese ion and the 
aluminum ion are both 1.0 M. This is the voltage of this cell at standard conditions. If the 
concentration of the manganese ion is increases, the forward reaction rate will increase, and 
the net movement of material in the forward direction will increase. This increase in the net 
movement of material in the forward direction will cause the cell voltage to be higher. If the 

www.ckl2.org 356 



concentration of the aluminum ion is decreased, the reverse reaction rate will decrease, and 
the net movement of material in the forward direction will increase. This increase in the net 
movement of material in the forward direction causes the voltage to be higher. If the [Mn 2+ ] 
concentration is decreased, the forward reaction rate will decrease, and the net movement 
of material in the forward direction will decrease. Therefore, the voltage of the cell will be 
lower. If the [A/ 3+ ] concentration is increased, the reverse reaction rate will be increased, 
and the net movement of material in the forward direction will decrease. Therefore, the 
voltage of the cell will be lower. 

Cells that do not have the concentrations of ions at 1.0 M are called non-standard cells. In 
the cell described above, [Mn 2+ ] > 1.0 M will cause the cell voltage to be greater than 0.48 
V and [A/ 3+ ] > 1.0 M will cause the cell voltage to be less than 0.48 volts. Vice versa would 
be true if the concentrations were less than 1.0 M. 

Cell voltages for non-standard cells can also be calculated using the Nernst Equation. 

The Nernst Equation is E = E° - ( 0,0591 )(Iog Q), where E is the voltage of the non-standard 
cell. E° would be the voltage of these reactants and products if they were a standard cell, n 
is the moles of electrons transferred in the balanced reaction, and Q is the reaction quotient. 
The reaction quotient is the equilibrium constant expression, but when the reaction is not 
at equilibrium it is called the reaction quotient. 

The reaction quotient for the example cell used here is Q = A /n2 +i 3 • 

The Nernst Equation for this cell is E = E° - (^^)(log ff^aX )- 

If you follow the mathematics for the case when both ions concentrations are 1.0 M, the 
reaction quotient would be 1 and the log of 1 is zero. Therefore, the second term in the 
Nernst Equation is zero and E = E°. 

Let's take the case of the example cell when [Mn 2+ ] = 6.0 M and [Al 3+ ] = 0.10 M. 

E = E o_ ( ^ i))(log J^ ) 

E = 0.48 V - (Mp )(log |f) 

E = 0.48 V - (3^p)(-4.33) 

E = 0.48 V - (-0.04 V) 

E = 0.52 V 

Concentration Cells 

If we attempt to construct a standard cell from the same two reactants, we do not get a 
reaction or a cell voltage. Suppose we attempt to build a cell with two silver half-cells. 



Ag {s) + Ag+ q) -► Ag+ q) + Ag {s) 

35 7 www.ckl2.org 



If this is a standard cell, the half-cell voltage for the oxidation half-reaction is -0.80 V and 
the half-cell voltage for the reduction half-reaction is +0.80 V. Clearly the net voltage is 0. 
It is possible, however, to produce a voltage using the same two half-reactions if we alter the 
concentrations of the ions. Such a cell is called a concentration cell and its voltage can be 
calculated using the Nernst Equation. 

The Nernst Equation would look like this: 

E = E° - ( °' ^ 91 )(log \ A 9 + { ), where the silver ion concentration in the numerator is the concen- 
tration of the silver ion in the products and the silver ion concentration in the denominator 
is the silver ion concentration in the reactants. 

Suppose we build this cell using a concentration of silver ion in the products of 0.010 M and 
a silver ion concentration in the reactants of 6.0 M. The E° in this case is zero and n = 1. 

E = E o_ ( CUMl )(log j^l ) 

E = 0V-(0.0591)(log«) 
E = V-(0.0591)(-2.78 V) 
E = V - (- 0.16 V) 
E = 0.16 V 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Electrochemistry. 
60 Minute Class Periods per Lesson 

Table 28.1: 

Lesson Number of Class Periods 

28.1 Origin of the Term Oxidation 0.5 

28.2 Oxidation- Reduction 2.0 

28.3 Balancing Redox Equations Using the 2.0 
Oxidation Number Method 

28.4 Electrolysis 2.0 

28.5 Galvanic Cells 2.0 



www.ckl2.org 358 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Electrochemistry. 

Electrochemistry Materials List 

Table 28.2: 



Lesson 



Strategy or Activity 



Materials Needed 



28.1 

28.2 



28.3 

28.4 
28.5 



Engagement Activity 



Pre-1982 penny, 100 mL 
flask, concentration nitric 
acid 



Multimedia Resources 

You may find these additional internet resources helpful when teaching Electrochemistry: 

• Gummy Bear Terminator Demo: http : //quiz2 . chem . ar izona . edu/preproom/Demo / 
20Files/gummi_bear_terminator . htm 

• Oxidation-reduction demos: http : //sites . google . com/site/chemistrydemos/7--cheiiicial-rea 
oxidation- reduction 

• Electrochenical Cell animation: http : //chemmovies . unl . edu/ChemAnime/ECZCELLD/ 
ECZCELLD.html 

• Electroplating lesson: http://www.finishing.com/faqs/howworks.html 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 



Standard Addressed by the Lessons in Electrochemistry 

359 



www.ckl2.org 



Table 28.3: 



Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 



28.1 

28.2 3g 

28.3 3g 
28.4 

28.5 



28.3 Lesson 28.1 Origin of the Term Oxidation 
Key Concepts 

In this lesson students learn the phlogiston and Lavoisier theories of combustion. 

Lesson Objectives 

• The students will define the term "oxidation." 

Lesson Vocabulary 

combustion A group of chemical reactants in which the reactants are fuel and oxygen gas. 
phlogiston The "fire substance" from a former theory of combustion. 

Strategies to Engage 

• Review key concepts students have already explored that relate to this lesson by asking 
what they already know about combustion. Use this opportunity to gauge student 
understanding of the properties of liquids and to clear up any misconceptions. 

Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side, and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI(LPR) 

www.ckl2.org 360 



Strategies to Extend and Evaluate 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 28.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

28.4 Lesson 28.2 Oxidation-Reduction 
Key Concepts 

In this lesson students explore oxidation, reduction, oxidation numbers, and oxidizing and 
reducing agents. 

Lesson Objectives 

• The students will assign the correct oxidation number to any element in a compound 
or ion. 

• In an oxidation-reduction equation, the students will identify the substance being ox- 
idized, the substance being reduced, the oxidizing agent, and the reducing agent 

Lesson Vocabulary 

oxidation 

1. A chemical combination with oxygen (old definition). 

2. A loss of electrons in an atom or an increase in the oxidation state of an atom (modern 
definition). 

oxidation numbers In ionic compounds, it is equal to the ionic charge. In covalent com- 
pounds, it is the charge assigned to the atom in accordance with a set of rules. 

361 www.ckl2.org 



oxidation state In ionic compounds, it is equal to the ionic charge. In covalent com- 
pounds, it is the charge assigned to the atom in accordance with a set of rules. 

oxidizing agent A substance that gains electrons in a chemical reaction or undergoes an 
increase in its oxidation state. 

reducing agent The substance in a redox reaction that loses electrons or increases its 
oxidation state. 

reduction The gain of electrons or decrease in oxidation state in a chemical reaction. 

Strategies to Engage 

• Have students set up a two-column table. Have them label one column "oxidation" 
and the other column "reduction". As you explore the information in this lesson, have 
students write notes in the appropriate column. 

• This demonstration must be performed in a fume hood. Add an old copper penny 
(pre-1982) to a lOOmL flask containing 30mL of concentrated nitric acid. Nitric acid 
oxidizes copper metal to produce copper nitrate. Nitric acid is highly corrosive. The 
gas produced in this reaction is highly toxic. 

Strategies to Explore 

• It may be helpful for students to remember LEO the lion goes GER. LEO = loss of 
electrons is oxidation and GER = gain of electrons is reduction. 

• Emphasize to students that although some reactions are referred as oxidation, reduction 
always accompanies oxidation. 

• Have students write a paragraph to compare and contrast the old and new definitions 
of oxidation. 

Strategies to Extend and Evaluate 

• Encourage interested groups of students to create Keynote or PowerPoint slideshows 
explaining redox reactions, oxidizing and reducing agents, and assigning oxidation 
numbers to share with the rest of the class. Students should include and examples of 
each concept. 

www.ckl2.org 362 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 28.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

28.5 Lesson 28.3 Balancing Redox Equations Using the 
Oxidation Number Method 

Key Concepts 

In this lesson students explore the oxidation number method of balancing redox equations. 

Lesson Objectives 

• Given a redox reaction, the students will determine which substances are changing 
their oxidation state. 

• Given a redox reaction, the students will balance the equation using the oxidation 
number method. 

Lesson Vocabulary 
Strategies to Engage 

• Before beginning this lesson, review with students how to assign oxidation numbers 
and how to identify the substances in equation that are oxidized and reduced. Use this 
opportunity to gauge student understanding of the key concepts explored so far in this 
chapter, and to clear up any misconceptions. 

Strategies to Explore 

• Use the mathematical calculations in this lesson to reduce the reliance on language 
skills. As you go through each example problem, use them to explain the concepts 

363 www.ckl2.org 



explored so far in this chapter. DI (ELL) 

Strategies to Extend and Evaluate 

Lesson Worksheets 

Copy and distribute the Lesson 28.3 worksheet titled Balancing Redox Equations in the 

Supplemental Workbook. Ask students to complete the worksheets alone or in pairs as a 
review of lesson content. 

Review Questions 

Have students answer the Lesson 28.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

28.6 Lesson 28.4 Electrolysis 
Key Concepts 

In this lesson students explore electrolysis and electrolysis apparatus. 

Lesson Objectives 

• Given a diagram of an electrolysis apparatus including the compound being elec- 
trolyzed, the students will identify the anode and the cathode. 

• Given a diagram of an electrolysis apparatus including the compound being elec- 
trolyzed, the students will write the oxidation and reduction half-reactions. 

Lesson Vocabulary 

anode The electrode at which oxidation occurs. 

battery A group of two or more cells that produces an electric current. 

cathode The electrode at which reduction occurs. 
www.ckl2.org 364 



electrolysis A chemical reaction brought about by an electric current. 

electroplating A process in which electrolysis is used as a means of coating an object with 
a layer of metal. 

Strategies to Engage 

• Facilitate a discussion with students about their knowledge of electroplated objects 
such as jewelry. Use this opportunity to gauge student understanding, address mis- 
conceptions, and generate curiosity for the concepts explored in this lesson. 

Strategies to Explore 

• Use Figure 3 and Figure 4 to explain as many concepts as possible. DI (ELL) 

Strategies to Extend and Evaluate 

• Have students do library research on the topic of real-life applications of electrochem- 
istry such as antioxidant compounds, water purification and batteries. Then have 
students prepare a written report, Keynote or PowerPoint slideshow, or poster dis- 
play. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 28.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 



28.7 Lesson 28.5 Galvanic Cells 
Key Concepts 

In this lesson students explore redox reactions that occur in galvanic cells. 

365 www.ckl2.ore 



Lesson Objectives 

• The students will describe the conditions necessary for a cell to be standard cell. 

• Given a table of standard reduction potentials and a diagram or description of a Gal- 
vanic cell, the students will balance the redox equation, calculate the standard cell 
potential, and determine the direction of electron flow in the external circuit. 

Lesson Vocabulary 

anode The electrode at which oxidation occurs. 

cathode The electrode at which reduction occurs. 

electrochemical cell An arrangement of electrodes and ionic solutions in which a spon- 
taneous redox reaction is used to produce a flow of electrons in an external circuit. 

salt bridge A U-shaped tube containing an electrolyte that connects two half-cells in an 
electrochemical cell. 

voltage The potential difference between two points in an electric circuit. 

Strategies to Engage 
Strategies to Explore 

• Ask students to look at Figure 8 and use write a paragraph to describe what is hap- 
pening in the illustration. Instruct students to use each vocabulary term at least one 
time within the paragraph. 

Strategies to Extend and Evaluate 

• Have students play a review game called "Two Truths and a Lie" using what they 
know about electrochemistry. To do this, pair students, and have each pair write 
three statements, two of which are facts about electrochemistry, and one of which is a 
plausible "lie." Then have each pair join with two other pairs to share what they wrote 
and try to guess which of the statements are "lies" and which are "truths." 

• Have students use grid paper to make a crossword puzzle using the vocabulary terms in 
this chapter. Ask students to exchange papers with a classmate and solve each other's 
puzzles. 

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• As a review of chapter vocabulary, have students divided a sheet of paper into three 
columns. Have students label the columns: Terms I know, Terms I think I know, 
and Terms I need to learn. Have them write the vocabulary terms in the appropriate 
column. Have them attempt to define the vocabulary terms in the first two columns, 
then check their answers. Instruct students to create flash cards for terms in the last 
columns along with any terms from the first two columns that they did not define 
correctly. 

Lesson Worksheets 

Copy and distribute the Lesson 28.5 worksheet titled Electrochemical Cells in the Sup- 
plemental Workbook. Ask students to complete the worksheets alone or in pairs as a review 
of lesson content. 

Review Questions 

Have students answer the Lesson 28.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided to teachers upon request. Please send an email to 
teachers-requests@ckl2.org. 

Chapter 28 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 28 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



367 www.ckl2.org 



www.ckl2.org 368 



Chapter 29 

TE Nuclear Chemistry 



29.1 Unit 12 Nuclear Chemistry 
Outline 

This unit, Nuclear Chemistry, includes one chapter that is an introduction to radioactivity, 
nuclear equations, and nuclear energy. 

• Chapter 29 Nuclear Chemistry 

Overview 

Nuclear Chemistry This chapter is an introduction to radioactivity, nuclear equations, 
and nuclear energy. 

29.2 Chapter 29 Nuclear Chemistry 
Outline 

The chapter Nuclear Chemistry consists of seven lessons that serve as an introduction to 
radioactivity, nuclear equations, and nuclear energy. 

• Lesson 29.1 The Discovery of Radioactivity 

• Lesson 29.2 Nuclear Notation 

• Lesson 29.3 Nuclear Force 

369 www.ckl2.org 



• Lesson 29.4 Nuclear Disintegration 

• Lesson 29.5 Nuclear Equations 

• Lesson 29.6 Radiation Around Us 

• Lesson 29.7 Applications of Nuclear Energy 

Overview 

In these lessons, students will explore: 

The discovery of radioactivity and common emissions from naturally radioactive nuclei. 

Nuclear symbols and the information contained in them. 

The relationship between nuclear force and nuclear energy. 

Radioactive decay. 

Equations for nuclear transmutations. 

Common nuclear emissions and half-life. 

Uses of radiation and nuclear energy. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Carbon- 14 Dating 



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o7l www.ckl2.org 



Table 29.1: (continued) 



Table 29.1: 



If you're a fan of the televi- 
sion CSI shows or other mys- 
tery or crime programming, 
you are probably aware of 
different means to estimate 
the timing of the poor un- 
fortunate's demise, dealing 
with factors such as body 
temperature, etc. For an 
archaeologist or an anthro- 
pologist, the trail of evi- 
dence is much colder. In the 
late 1940's, Willard Libby 
of the University of Chicago 
devised a method to estab- 
lish the age of even the old- 
est unearthed fossils based 
on the remaining amount 
of radioactive 14 C. This 
isotope is one of three for 
the element carbon, which is 
ubiquitous in living systems. 
Carbon has an atomic num- 
ber of six, and exists in three 
nuclear configurations: with 
six, seven and eight neutrons 
respectively. Thus the 14 C 
isotope has a nucleus con- 
sisting of six protons and 
eight neutrons. This as- 
sembly spontaneously de- 
cays into Nitrogen-14 and 
the release of beta radiation. 
Radioisotopic carbon has 
been measured to decay at a 
constant rate, with half the 
initial amount remaining, af- 
ter 5730 years. If it is as- 
sumed that the 14 C is not 
replaced, the loss of 14 C sug- 
sges*sdfciS.<ttgLe interval since 
the artifact last exchanged 
CO2 with the atmosphere. 



372 



Cosmic Radiation 



Neutron 



Cosmic rays ™ 
create an energetic 
neutron. 



1- 



The C reacts with O 2 in the a 



Plants take up 
carbon dioxiri^ 

14 



including CO 2 
during 
photo synthesi 




{Source: CK12 Foundation, 
Author: Richard Parsons, 
License: CC-BY-SA) 



Table 29.1: (continued) 



When the ratio of the remaining amount of 14 C to 12 C is compared to the same ratio in a 
living organism, the amount of time elapsing since the organism's death can be analyzed. 

Thus, over time, in any material that contains the element carbon, the amount of remaining 
14 C in a sample is an indicator of the age of the artifact. 

One of the best-known applications of this technique was in the analysis of Otzi, the alpine 
Ice Man. Found in a region straddling the Austrian-Italian border, by hikers in 1991, Otzi 
was the name given to the partially mummified remains of a hunter located still frozen into a 
glacier. Otzi provided a wealth of information to anthropologists in that he was still dressed 
with fur boots, and a pack with tools including a copper hatchet and arrows. Researchers 
even discovered the menu of his last meal, probably deer meat and wheat bran, by analyzing 
his stomach contents. Analysis of small tissue samples from his corpse suggest that he lived 
from 5300 to 5100 years ago, before the Bronze Age. The construction and contents of 
his clothing and possessions provide an invaluable insight into the culture and technological 
sophistication of his age. 

Other applications of this technology include dating of the Dead Sea scrolls, and analysis of 
the time period of the cave art found in central Europe. Ocean sediment samples, and even 
a meteorite believed to have originated on Mars! 

Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Nuclear Chemistry. 
60 Minute Class Periods per Lesson 

Table 29.2: 

Lesson Number of Class Periods 

29.1 The Discovery of Radioactivity 1.0 

29.2 Nuclear Notation 1.0 

29.3 Nuclear Force 1.0 

29.4 Nuclear Disintegration 1.5 

29.5 Nuclear Equations 1.5 

29.6 Radiation Around Us 1.0 

29.7 Applications of Nuclear Energy 1.0 



373 www.ckl2.org 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Nuclear Chemistry. 

Nuclear Chemistry Materials List 

Table 29.3: 



Lesson 



Strategy or Activity 



Materials Needed 



29.1 



29.2 
29.3 
29.4 
29.5 
29.6 
29.7 



Exploration Activity 



Exploration Activity 
Exploration Activity 



Self-developing film, various 
sources of low-level radia- 
tion. 



Dominoes 

Pennies, plastic bag or cup 



Multimedia Resources 

You may find these additional internet resources helpful when teaching Nuclear Chemistry: 



Balancing beta decay equations animation: http : //chemmovies . unl . edu/ChemAnime/ 

BBETAD/BBETAD . html 

Balancing alpha decay equations animation: http : //chemmovies . unl . edu/ChemAnime/ 

ALPHAD/ALPHAD . html 

"Splitting the Atom" lesson plan: http : //www . sciencenetlinks . com/lessons . php? 

BenchmarkID=10&#38 ; DocID=40 



Possible Misconceptions 

Identify: Students may think that radiation is harmful in all forms. 

Clarify: Radiation is the transfer of radiant energy by means of electromagnetic waves. 
The word radiation is sometimes used to describe the energy that travels in the form of 
electromagnetic waves (radiant energy). Although some forms of radiant energy are harmful, 
most are not. Radiation has many uses such as energy generation, industry, and medicine. 



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374 



Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Nuclear Chemistry 

Table 29.4: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

29.1 

29.2 lie 

29.3 11a, lib, llg 

29.4 lid, lie, llg 

29.5 lib 

29.6 li, lie, lie, llf 

29.7 If, lib 



29.3 Lesson 29.1 Discovery of Radioactivity 
Key Concepts 

In this lesson students explore the discovery of radioactivity and common emissions from 
naturally radioactive nuclei. 



Lesson Objectives 

• The students will describe the roles played by Henri Becquerel and Marie Curie played 
in the discovery of radioactivity. 

• The students will list the most common emissions from naturally radioactive nuclei. 



Lesson Vocabulary 

alpha particle An alpha particle is a helium— 4 nucleus. 

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beta particle A beta particle is a high speed electron, specifically an electron of nuclear 
origin. 

gamma ray Gamma radiation is the highest energy on the spectrum of electromagnetic 
radiation. 

Marie Curie Marie Curie was a physicist and chemist of Polish upbringing, and subse- 
quently, French citizenship; a pioneer in the field of radioactivity, and the only person 
to ever win two Nobel prizes in science. 

Strategies to Engage 

• Review with students the structure of the atom by drawing a model on the board. 
Point out to students that chemical reactions involve electrons. Explain to students 
that in this chapter, they will explore nuclear reactions. Tell students that the focus 
will shift from the electrons to the nucleus, because nuclear reactions involve changes 
within the nucleus of the atom. 

• Ask students what they remember about Rutherford's gold foil experiment. Explain 
to students that Rutherford knew that alpha particles were emitted by radioactive 
material, and that in this lesson they will learn more about these and other emissions 
from naturally radioactive nuclei. 

• Students are likely to have heard about radiation in advertising and popular media 
(e.g., medicine, comic books, cartoons). Call on volunteers to share with the class 
anything they already know about radiation. Point out correct responses and clear up 
any misconceptions. Tell students they will learn more about radiation in this chapter. 

Strategies to Explore 

• Have students create a chart summarizing the properties of alpha particles, beta parti- 
cles, and gamma rays explored in this lesson. Have students add information explored 
in the rest of the chapter. 

• Have students write a newspaper article announcing the discovery of radioactivity. 
Encourage them to use factual information explored so far in this lesson. 

• You can model the discovery of radioactivity by performing this simple demonstration. 
Cover self- developing film with heavy black paper to prevent visible light from exposing 
the film. Place an item that is a source of low-level radiation such as an ionizing 

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smoke detector, antique ceramic dishware, a radium-dial watch face, or a weighted tape 
dispenser on top of the film, and put it in a location where it can be left undisturbed 
for several days. 

Strategies to Extend and Evaluate 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 29.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



29.4 Lesson 29.2 Nuclear Notation 
Key Concepts 

In this lesson students explore nuclear symbols and the information contained in them. 

Lesson Objectives 

• The students will state the information contained in the atomic number of a nucleus. 

• The students will state the information contained in the mass number of a nucleus. 

• The students will subtract the atomic number from the mass number to determine the 
number of neutrons in a nucleus. 

• Students will read and write complete nuclear symbols (know the structure of the 
symbols and understand the information contained in them). 

Lesson Vocabulary 

atomic number The atomic number indicates the number of protons in the nucleus. 

mass number The mass number indicates the number of protons plus the number of 
neutrons in the nucleus. 



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electron An electron is a fundamental sub-atomic particle that carries a negative charge. 

neutron A neutron is a sub-atomic particle with no electric charge and a mass slightly 
larger than a proton. 

proton A proton is a fundamental sub-atomic particle with a net positive charge. 

nucleus The nucleus of an atom if the very dense region, consisting of nucleons (proton 
and neutrons) at the center of an atom. 

nuclei Nuclei is the plural of nucleus. 

nucleon A nucleon is a constituent part (proton or neutron) of an atomic nucleus. 

nuclide A type of nucleus specified by its atomic number and mass number. 

Strategies to Engage 

• Have students look at Figure 2. Review with students the information contained in a 
nuclear symbol, the definitions of both mass numbers and atomic numbers, and how 
to use the nuclear symbol to determine the number of protons, neutrons, and electrons 
in an atom of an element. Use this opportunity to gauge student understanding and 
address misconceptions about the concepts explored in this lesson. 

• Preview the lesson vocabulary to find out what your students already know about the 
concepts to be explored in this lesson. Have students define each vocabulary term. At 
the end of the lesson encourage students to go back and write the correct definition for 
each incorrect definition. 

Strategies to Explore 

Strategies to Extend and Evaluate 

• As a review of lesson content, have students create a ten-question quiz about the key 
concepts explored in this lesson. Have students exchange papers with another student 
who then takes the quiz. Have them hand the papers back to the original student who 
will assign a grade. Encourage students to discuss any incorrect answers. 

• Have students write a one-paragraph summary of this lesson. Instruct students to 
correctly use each vocabulary term at least one time in the summary. 

www.ckl2.org 3/8 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 29.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

29.5 Lesson 29.3 Nuclear Force 
Key Concepts 

In this lesson students explore nuclear force and nuclear energy. 

Lesson Objectives 

• Students will compare the energy released per gram of matter in nuclear reactions to 
that in chemical reactions. 

• Students will express the equation for calculating the change in mass during nuclear 
reactions that is converted into energy. 

• Students will express the relationship between nuclear stability and the nuclei's binding 
energy per nucleon ratio. 



Lesson Vocabulary 

binding energy Binding energy is the amount of energy that holds a nucleus together, 
and therefore, also the amount of energy required to decompose a nucleus into its 
component nucleons. 



mass defect Mass defect is the difference between the sum of the masses of the nuclear 
components and the mass of the corresponding nucleus. Much of this lost mass is 
converted into binding energy. 

nucleon Nucleon is a collective name for neutrons and protons. 

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Strategies to Engage 

• Ask students if they have ever wondered how the protons and neutrons are able to 
remain together in the nucleus when neutrons are neutral, protons are positive, and 
like charges repel. Explain to students that in this chapter they will learn how this is 
possible. You may want to allow students to come up with their own explanations and 
discuss their ideas as a class. 

Strategies to Explore 

• On the board or chart paper, outline the main concepts of the lesson as a class. Discuss 
the main concepts as you prepare the outline. 

Strategies to Extend and Evaluate 

• Have students do library research on Einstein's equation, E=mc2 and prepare a written 
report, Keynote or PowerPoint slideshow, or poster display. 

Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 29.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



29.6 Lesson 29.4 Nuclear Disintegration 
Key Concepts 

In this lesson students explore radioactive decay. 

Lesson Objectives 

• Students will list some naturally occurring isotopes of elements that are radioactive. 
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Students will describe the three most common emissions during natural nuclear decay. 

Students will express the changes in the atomic number and mass number of radioactive 

nuclei when an alpha particle is emitted. 

Students will express the changes in the atomic number and mass number of radioactive 

nuclei when a beta particle is emitted. 

Students will express the changes in the atomic number and mass number of radioactive 

nuclei when a gamma ray is emitted. 

Students will express that protons and neutrons are not indivisible and are composed 

of particles called quarks. 

Students will express the number of quarks that make up a proton or neutron. 



Lesson Vocabulary 

alpha decay Alpha decay is a common mode of radioactive decay in which a nucleus emits 
an alpha particle (a helium— 4 nucleus). 



beta decay Beta decay is a common mode of radioactive decay in which a nucleus emits 
beta particles. The daughter nucleus will have a higher atomic number than the original 
nucleus. 



quark Quarks are physical particles that form one of the two basic constituents of matter. 
Various species of quarks combine in specific ways to form protons and neutrons, in 
each case taking exactly three quarks to make the composite particle. 



Strategies to Engage 

• Have students read the lesson objectives. Ask students to write down and try to 
complete each objective. Instruct students to use a scale of 1-5 to record how sure they 
are that they have correctly completed each objective (1= not, 5 = very sure). As you 
explore this lesson, encourage students to change their answers as necessary. 



Strategies to Explore 

• Have less proficient readers make a main ideas/details chart as they read the lesson,. 
Instruct them to divide a sheet of paper down the middle and record the main ideas 
on the left side and the details for each main idea on the right side. Have students 
save their chart for reviewing lesson content. DI(LPR) 



381 www.ckl2.org 



Strategies to Extend and Evaluate 

• Have a group of interested students do library research on how quarks were named. 
Students should be prepared to share their findings with the rest of the class. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 29.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



29.7 Lesson 29.5 Nuclear Equations 
Key Concepts 

In this lesson students explore equations for nuclear transmutations. 

Lesson Objectives 

• The students will give definitions and examples of fission and fusion. 

• The students will classify nuclear reactions as fission or fusion. 

• Given a nuclear equation with one species missing, the student will be able to correctly 
fill in the missing particle. 

• Students will write balanced equations for nuclear transmutations. 

Lesson Vocabulary 

artificial radioactivity Induced radioactivity that is produced by bombarding an element 
with high- velocity particles. 

chain reaction A multi-stage nuclear reaction that sustains itself in a series of fissions in 
which the release of neutrons from the splitting of one atom leads to the splitting of 
others. 

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critical mass The smallest mass of a fissionable material that will sustain a nuclear chain 
reaction at a constant level. 



fission A nuclear reaction in which a heavy nucleus splits into two or more smaller frag- 
ments, releasing large amounts of energy. 



fusion A nuclear reaction in which nuclei combine to form more massive nuclei with the 
simultaneous release of energy. 



natural radioactivity The radioactivity that occurs naturally, as opposed to induced 
radioactivity. Also known as spontaneous fission. 



Strategies to Engage 

• Have students read the review questions at the end of this section. This way, students 
will be familiar with the types of information that they will explore in this section. 



Strategies to Explore 

• Point out to students that although mass and atoms are not conserved in nuclear 
reactions like they are in chemical reactions, total mass number and total atomic 
number are conserved. So, in a nuclear equation the sum of the mass numbers of the 
reactants must equal the sum of the mass numbers of the products, and the sum of 
the charges of the reactants must equal the sum of the charges of the products. 



Have students write a shot lesson comparing and contrast nuclear and chemical equa- 
tions. Instruct students to include examples of each type of equation. 



Have students create a Venn diagram comparing and contrasting nuclear fusion and 
fission. 



Give groups of students a set of dominoes and challenge them to set up the dominoes in 
a way that will most closely model a nuclear chain reaction. The correct arrangement 
would resemble a triangle, where knocking down one domino would cause two to fall, 
and those two would each cause more to fall and so on. 



383 www.ckl2.org 



Strategies to Extend and Evaluate 

Lesson Worksheets 

Copy and distribute the Lesson 29.5 worksheet titled Nuclear Chemistry in the Supple- 
mental Workbook. Ask students to complete the worksheets alone or in pairs as a review of 
lesson content. 



Review Questions 

Have students answer the Lesson 29.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



29.8 Lesson 29.6 Radiation Around Us 
Key Concepts 

In this lesson students explore common nuclear emissions and half-life. 

Lesson Objectives 

• Students will calculate the amount of radioactive material that will remain after an 
integral number of half-lives. 

• Students will describe how carbon-14 is used to determine the age of carbon containing 
objects. 

• Students will qualitatively compare the ionizing power and penetration power of a, j3, 
and 7 particles. 

Lesson Vocabulary 

background radiation Radiation that comes from environment sources including the 
earth's crust, the atmosphere, cosmic rays, and radioisotopes. These natural sources 
of radiation account for the largest amount of radiation received by most people. 

half-life The half-life of a radioactive substance is the time interval required for a quantity 
of material to decay to half its original value. 

www.ckl2.org 384 



Strategies to Engage 

• Students are likely to have heard about radiation in advertising and popular media 
(e.g., medicine, comic books, cartoons). Call on volunteers to share with the class 
anything they already know about radiation. Point out correct responses and clear up 
any misconceptions. Tell students they will learn more about radiation in this chapter. 



Strategies to Explore 

• Use pennies to model half-life. Place 50 pennies in a bag or cup. Shake for 10 seconds. 
Gently pour out the pennies. Count the number of pennies that are heads up. Explain 
to students that these are the "decayed atoms. Return only the pennies that are tails 
up to the bag and shake for 10 seconds. Count the number of pennies that are heads 
up. Explain to students that these are the "decayed" atoms. Continue, shaking and 
counting until all the atoms have decayed. Instruct students to prepare a graph of 
number of decayed atoms vs. time. Have students write a paragraph explaining how 
this activity relates to isotopes, half-life, and radioactivity. 



Strategies to Extend and Evaluate 

• Before the health effects of radiation were known and understood, products that contain 
radioactive isotopes such as radium were thought to be good for you. Have students 
research some of these products and present their findings to the class. 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 29.6 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



385 www.ckl2.org 



29.9 Lesson 29.7 Applications of Nuclear Energy 
Key Concepts 

In this lesson students explore uses of radiation and nuclear energy. 

Lesson Objectives 

• The students will trace the energy transfers that occur in a nuclear power reactor from 
the binding energy of the nuclei to the electricity that leaves the plant. 

• The students will define the term "breeder reactor." 

• The students will list some medical uses of nuclear energy. 

Lesson Vocabulary 

control rods Control rods are made of chemical elements capable of absorbing many neu- 
trons and are used to control the rate of a fission chain reaction in a nuclear reactor. 

cyclotron A cyclotron is a type of particle accelerator. 

fall out Fall out is radioactive dust hazard from a nuclear explosion, so named because it 
"falls out" of the atmosphere where it was spread by the explosion. 

fissile A fissile substance is a substance capable of sustaining a chain reaction of nuclear 
fission. 

fissionable A fissionable material is material capable of undergoing fission. 

Geiger counter A Geiger counter is an instrument used to detect radiation, usually alpha 
and beta radiation, but some models can also detect gamma radiation. 

isotope Nuclei with the same number of protons but different numbers of neutrons. 

linear accelerator A linear accelerator is a linear electrical device for the acceleration of 
subatomic particles. 

moderator A neutron moderator is a medium which reduces the velocity of fast neutrons; 
commonly used moderators are regular (light) water, solid graphite, and heavy water. 

nuclear pile A nuclear pile is a nuclear reactor. 

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Strategies to Engage 
Strategies to Explore 

• Have teams of students debate the use of nuclear reactions as an alternative source of 
energy. 

Strategies to Extend and Evaluate 

• Have students research the Chernobyl disaster's effect on biological systems. Students 
should prepare a written report of their findings. 

• Students are likely to have heard about radioactivity in popular media. Have students 
bring in examples of bad science related to radioactivity from the web or from books, 
including comic books. Have them quote the claim, reference the source, and explain 
what is wrong. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 29.7 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 29 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 29 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



38 7 www.ckl2.org 



www.ckl2.org 388 



Chapter 30 

TE Organic Chemistry 



30.1 Chapter 30 Organic Chemistry 
Outline 

This unit, Organic Chemistry, includes one chapter that introduces the structure and nomen- 
clature of straight chain hydrocarbons, aromatic hydrocarbons, and the functional groups of 
hydrocarbons. 

• Chapter 30 Organic Chemistry 

Overview 

Organic Chemistry 

This chapter introduces the structure and nomenclature of straight chain hydrocarbons, 
aromatic hydrocarbons, and the functional groups of hydrocarbons. 

Chapter 30 Organic Chemistry 
Outline 

The chapter Organic Chemistry consists of five lessons that introduce the structure and 
nomenclature of straight chain hydrocarbons, aromatic hydrocarbons, and the functional 
groups of hydrocarbons. 

• Lesson 30.1 Carbon, A Unique Element 

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• Lesson 30.2 Hydrocarbons 

• Lesson 30.3 Aromatics 

• Lesson 30.4 Functional Groups 

• Lesson 30.5 Biochemical Molecules 

Overview 

In these lessons, students will explore: 

• Properties of carbon. 

• The definition, naming, and drawing of alkanes, alkenes, and alykynes. 

• Compounds that contain benzene. 

• Categories of organic compounds that have distinguishing functional groups. 

• Categories of biochemical molecules. 

Science Background Information 

This information is provided for teachers who are just beginning to instruct in this subject 
area. 

Trans Fats 

Twenty-first century Americans are becoming increasingly cognizant of the role of dietary 
fats in their long-term health considerations. Many consumers seek to limit the amount of 
fats in their diets to minimize their risk of developing coronary heart disease. In particular, 
one category of fats appears to be linked to several contributory mortality risks: Trans Fats. 
The chemical structure of this class of compounds consists of long hydrocarbon chains, with 
one or more trans-configured alkene groups within the chain. Naturally occurring animal 
fats generally consist of fully hydrogenated or saturated fatty acids, lacking alkene C=C 
bonds. 

In the 1960s, health concerns about saturated fats led to the popularity of unsaturated 
or partially hydrogenated fatty acids. Also the lower cost of these mainly vegetable oils 
increased their adoption. These naturally occurring unsaturated fats are usually liquids, due 
to their predominantly cis-alkene configuration, which produces a "bent" structure that does 
not pack well. Consumer demand for solid fats, for example, "spreadable" margarines, lead 
to the application of chemical hydrogenation. Adding hydrogen atoms across the cis C=C 
bonds can yield the completely saturated fat, or it can also lead to partial hydrogenation. In 
this case, the C=C bonds do not become fully saturated, but instead the alkene bonds twist 
to the trans configuration. Unlike the cis-alkene fats, with their bent shape, the trans fats 
are more linear in shape and like their fully saturated congeners, they pack more effectively 
and can be produced as solids. Trans fats are also less likely to be attacked by atmospheric 
radicals and are therefore less vulnerable to rancidity. Their shelf life increases dramatically. 

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The link between trans fat consumption and heart disease is strongly supported by many 
medical studies. Other health effects linked to the use of trans fats include liver dysfunctions; 
due to the synthetic nature of trans fats, they may not metabolize in the same way as other 
fats. 

Recently, several municipalities, such as New York City, Philadelphia and San Francisco, 
have limited or banned outright the use of trans fats in food preparation. The Food and 
Drug Administration (FDA) now require food manufacturers to list the presence of trans 
fats on food labels. 

Ozone's Role in the Atmosphere 

We live on a planet uniquely situated in what astronomers refer to as our solar system's 
habitable zone. This region can be described as one in which the proper temperature range, 
elemental composition, and physical conditions have allowed life forms to exist and flourish 
for billions of years. An appropriate climate range, and the right array of elements, along with 
sufficient mass for a gravitational, pull enabled Earth to develop a protective atmosphere. 
The presence of oxygen gas, 2 , causes incoming space debris to burn up usually before 
reaching the surface. In a similar fashion, an allotrope of oxygen, called ozone, O3, filters 
out much of the ultraviolet, B radiation (wavelengths between 280 and 320 nm) reaching 
Earth from the solar system. This type of radiation is a cause for concern in that it is linked 
with DNA mutations, particularly those associated with skin melanoma and carcinoma. 

3 + UV -► O + 2 

O + 3 -► 2 2 



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Table 30.1: (continued) 



Table 30.1: 



Nobel Laureate, F. Sher- 
wood Rowland, and his re- 
search team at the Univer- 
sity of California Irvine, in 
the 1970s discovered that 
the amount of ozone found 
in the stratosphere was di- 
minishing. They found that 
this depletion could be as- 
sociated with the cumula- 
tive amount of chlorofluoro- 
carbon gases in the atmo- 
sphere. These CFC's or as 
they are otherwise known, 
Freons, were non-degradable 
remains of consumer prod- 
ucts such as aerosol propel- 
lants and refrigerants. Their 
studies indicated that in the 
upper atmosphere, ozone 
was being split in the pres- 
ence of ultraviolet radiation 
into diatomic oxygen and 
oxygen radical atoms, which 
would, in turn react with the 
chlorofluorocarbons. The 
resulting chloride monoxide 
(CIO) radicals were iden- 
tified in the upper strato- 
sphere over Antarctica. This 
location is significant be- 
cause winter in the Southern 
Hemisphere (September & 
October) under the Antarc- 
tic vortex, results in the 
coldest winter temperatures 
on the planet. Under these 
conditions, any moisture in 
that locale exists only in the 
ice phase. The researchers 
found that the chlorofluoro- 
carbon/ozone reaction was 
catalyzed by the presence 
of certain types of ice crys- 
tals in the lower atmosphere. 
Atmosnheric measurements 




Figure 1: The purple area 

over Antarctica is low in 
ozone. The red area is 
higher in ozone. 
(Source: http: 

//commons . wikimedia . 
org/wiki/File : 
Hole_in_the_ozone.jpg) , 
License: This file is in the 
public domain because it 
was created by NASA.) 



393 



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Table 30.1: (continued) 



Increased ozone depletion has been linked, as mentioned earlier, with an increased risk of 
DNA mutations. This association has been supported by increasing levels of skin cancer in 
humans, animals, and even plants, in latitudes where significant ozone depletion is noted. In 
addition, other conditions, such as diminished immune response and a higher risk of earlier 
cataract development, appear to be linked with ozone depletion. 

Chlorofluorocarbon use has been largely phased out in developed countries, but their relative 
inertness leads to the situation that their influence will continue to be noted in the strato- 
sphere for the indefinite future. Many manufacturers now substitute HCFC's, (where one or 
more chlorine atoms have been replaced by hydrogen atoms). These molecules retain many 
of the desirable properties of chlorofluorocarbons without their contributions to atmospheric 
destruction. 



Pacing the Lessons 

Use the table below as a guide for the time required to teach the lessons of Chapter 30. 
60 Minute Class Periods per Lesson 

Table 30.2: 



Lesson 



Number of Class Periods 



30.1 Carbon, A Unique Element 

30.2 Hydrocarbons 

30.3 Aromatics 

30.4 Functional Groups 

30.5 Biochemical Molecules 



1.0 
2.0 
1.5 
2.0 
2.0 



Managing Materials 

The following items are needed to teach the strategies and activities described in the Teachers 
Edition of the FlexBook for Chapter 30. 

Chapter 30 Materials List 



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394 



Table 30.3: 



Lesson Strategy or Activity Materials Needed 

30.1 

30.2 

30.3 

30.4 Evaluation Activity Index Cards 

30.5 



Multimedia Resources 

You may find this additional web based resource helpful when teaching Chapter 30: 

• Introduction to Organic Chemistry: http : //www . visionlearning . com/library/module_ 
viewer . php?mid=60 

Possible Misconceptions 
Making the FlexBook Flexible 

An important advantage of the FlexBook is the ability it gives you, the teacher, to select the 
chapters and lessons that you think are most important for your own classes. You should 
also consult the standards correlation table that follows when selecting chapters and lessons 
to include in the FlexBook for your classes. 

Standard Addressed by the Lessons in Chapter 30 

Table 30.4: 

Lesson California Stan- NSES Standards AAAS Bench- 

dards marks 

30.1 10b 

30.2 lOd 

30.3 lOd 

30.4 lOe 

30.5 10a, 10c, lOf 



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30.2 Lesson 30.1 Carbon, A Unique Element 
Key Concepts 

In this lesson students explore the properties of carbon. 



Lesson Objectives 

• Describe the allotropes of carbon. 

• Describe the hybridization of carbon. 

• Explain how the hybridization of carbon allows for the formation of large number of 
compounds containing carbon. 



Lesson Vocabulary 

hybridization The process of combining sublevels to create a new sublevel. 

localized electrons Electrons that are stationary (have fixed positions) between the bond. 



delocalized electrons Electrons that are free to move between the bond (in multiple 
bonding). 



allotropes Different forms of the same element based on their bonding. 



Strategies to Engage 

• Explain to students that there are millions of compounds that contain the element 
carbon. Have students recall what they know about carbon. Facilitate a discussion 
with students about how carbon is able to join with other atoms in so many different 
ways. 



Strategies to Explore 

• Throughout this chapter, give students the opportunity to create three-dimensional 
models as much as possible. DI (ELL) 

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Strategies to Extend and Evaluate 

• Have students do library research on Percy Julian, an African American research 
chemist and prepare a written report, PowerPoint or Keynote slideshow, or display 



Lesson Worksheets 

There are no worksheets for this lesson. 



Review Questions 

Have students answer the Lesson 30.1 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



30.3 Lesson 30.2 Hydrocarbons 
Key Concepts 

In this lesson students explore the definition, naming, and drawing of alkanes, alkenes, and 
alykynes. 

Lesson Objectives 

Define alkanes as well as name and draw alkanes. 

Define alkenes as well as name and draw alkenes. 

Define alkynes as well as name and draw alkynes. 

Define structural formula. 

Define isomers and be able to draw isomers for alkanes, alkenes, and alkynes. 

Define substituted halogens as well as name and draw substituted halogens. 

Lesson Vocabulary 

alkanes Compounds containing carbon and hydrogen where the carbon bonds are all in- 
volved in single bonding. 

saturated compound Organic compound containing all single bonds. 

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structural formula The formula showing how the bonded atoms are arranged in the 
molecule. 

structural isomers Molecules that have the same molecular formula but different struc- 
tures. 

alkenes Organic compounds containing hydrogen and carbon but contain at least one 
double bonded carbon atom. 

unsaturated compound Organic compound that contain multiple bonding. 

alkynes Organic compounds containing carbon and hydrogen and at least one triple bond. 

substituted halogens organic compounds where one or more of the branches are a halo- 
gen. 

Strategies to Engage 
Strategies to Explore 

• Point out to students that after the first four alkanes in Table 1, the names begin with 
a prefix that identifies the number of carbon atoms in the chain. Challenge interested 
students to come up with a pneumonic device such as a silly sentence to memorize the 
names of the first four alkanes. 

• Have students set up a three column table to organize the information about alkanes, 
alkenes, and alkynes explored in this lesson. 

Strategies to Extend and Evaluate 

• Have groups of students do library research on the future of plastics. Ask some of the 
groups to find out about plastic superconductors, building materials, lasers, lumber, 
or other areas of interest. Have each group give an oral presentation of their findings. 

Lesson Worksheets 

Copy and distribute the Lesson 30.2 worksheet titled Organic Nomenclature in the Sup- 
plemental Workbook. Ask students to complete the worksheets alone or in pairs as a review 
of lesson content. 

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Review Questions 

Have students answer the Lesson 30.2 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



30.4 Lesson 30.3 Aromatics 
Key Concepts 

In this lesson students explore compounds that contain benzene. 



Lesson Objectives 

• Describe the bonding in benzene. 

• Define aromaticity. 

• Name simple compounds containing benzene. 

• Draw simple compounds containing benzene. 



Lesson Vocabulary 

aromatic A compound contains one or more benzene rings. 

benzene ring Equivalent resonance structures representing a 6— carbon ring with alter- 
nating C — C double bonds. 

hybrid A species with properties in-between the properties of the parents. 

resonance To have two of more equivalent Lewis diagrams representing a particular model. 



Strategies to Engage 

• Have students recall what they know about resonance. Use this opportunity to gauge 
student understanding, address misconceptions, and generate curiosity for the concepts 
explored in this lesson. 



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Strategies to Explore 

• Have students create a concept map relating the terms and objectives of the concepts 
explored in this lesson. 

Strategies to Extend and Evaluate 

• Have students work in small groups to create an advertisement for a compound con- 
taining benzene, such as glue, paint, or furniture solvents. It should resemble an ad 
that might appear in a newspaper or a magazine. Students should illustrate their ad 
and write a slogan. Allow ELL learners to work with another student who is more 
capable with the language. (ELL) 

• Have students write a one-paragraph summary of this lesson. Instruct students to 
correctly use each vocabulary term at least one time in the summary. 

Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 30.3 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 



30.5 Lesson 30.4 Functional Groups 
Key Concepts 

In this lesson students explore categories of organic compounds that have distinguishing 
functional groups. 

Lesson Objectives 

• Identify alcohols, aldehydes, ketones, ethers, organic acids, and esters based on their 
functional groups. 



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• Name and draw simple alcohols, aldehydes, ketones, ethers, organic acids, and esters. 

Lesson Vocabulary 

Alcohol an organic compound in which the hydroxyl group is a substituent on a hydro- 
carbon. 

Aldehyde an organic compound containing the carbonyl group bonded to the end of a 
hydrocarbon chain. 

Ketone an organic compound containing the carbonyl group bonded to a non-terminal 
carbon atom in a hydrocarbon chain. 

Organic acid a hydrocarbon chain ending in a carboxyl group. 

Ester an organic compound produced by the reaction between a carboxylic acid and an 
alcohol. 

Strategies to Engage 
Strategies to Explore 

• Point out to students that while the -OH bonding in bases is ionic, the C-O-H bonding 
in alcohols is covalent. 

• This lesson includes a description of categories of organic compounds that have distin- 
guishing functional groups. Before reading, prepare less proficient readers by having 
students write the following on the top of separate sheets of notebook paper: 

Alcohols 

Aldehydes 

Ketones 

Ethers 

Organic acids 

Esters 

As they read each section have them write key points under each heading. This will give 
the students a quick reference and help them to organize the information. Instruct students 
to write a one-paragraph summary of the information they have read in each section. DI 
(LPR) 

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Strategies to Extend and Evaluate 

• Write the names of the six categories of organic compounds explored in this lesson 
on separate index cards. Write their formulas on separate index cards. Have pairs of 
students compete with each other to correctly match the names with the formulas in 
the shortest amount of time. 



Lesson Worksheets 

Have students continue with the Organic Nomenclature worksheet started in lesson 30.2 . 

Review Questions 

Have students answer the Lesson 30.4 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

30.6 Lesson 30.5 Biochemical Molecules 
Key Concepts 

In this lesson students explore categories of biochemical molecules. 

Lesson Objectives 
Lesson Vocabulary 

carbohydrates Molecules that contain carbon, hydrogen, and oxygen and have the general 
formula C x (H20) y . 

monosaccharide A carbohydrate that is single sugar unit (i.e. glucose). 

disaccharide A carbohydrate that is two sugar units joined together (i.e. sucrose). 

polysaccharide A carbohydrate that is more than two sugar units joined together (i.e. 
starch). 

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lipids Fats and oils (triglycerides) produced for the purpose of storing energy. 

fatty acid A carboxylic acid having anywhere from four (4) carbon atoms to 36 carbon 
atoms. 

steroids Compounds where four carbon rings are bonded together with branches and func- 
tional groups bonded to the rings. 

phospholipids A combination of fatty acids, glycerol and a phosphate group joined to- 
gether. 

polymer A large organic molecule that contains hundreds or even thousands of atoms. 

amino acids Molecules that contain an amine group (—NH2) and a carboxyl group (-COOH). 

dipeptide Two amino acids joined together. 

polypeptide Many amino acids combined together. 

proteins Polymers that are amino acids. 

enzymes A subset of proteins that function to speed up a chemical reaction. 

DNA (deoxyribonucleic acid) DNA is a polynucleotide that carries our genetic coding; 
its function is to direct the body in the synthesis of proteins. 

Strategies to Engage 

• Students are likely to have heard about biochemical molecules in advertising and pop- 
ular media (e.g., low-fat foods, high-protein diets). Call on volunteers to share with 
the class anything they already know about biochemical molecules. Point out correct 
responses and clear up any misconceptions. Tell students they will learn more about 
biochemical compounds in this lesson. 

Strategies to Explore 

• On the board or chart paper, outline the main concepts of the lesson as a class. Discuss 
the main concepts as you prepare the outline. 

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Strategies to Extend and Evaluate 

• As a review of the chapter vocabulary, suggest that students make flash cards, with 
the vocabulary term on one side, and a drawing of what the term means on the other 
crossword puzzle. 

• Have students research and prepare lists of carbohydrates in food, clothing, and shelter. 
Discuss findings as a class. 



Lesson Worksheets 

There are no worksheets for this lesson. 

Review Questions 

Have students answer the Lesson 30.5 Review Questions that are listed at the end of the 
lesson in their FlexBook. 

Answers will be provided upon request. Please send an email to teachers- 
requests@ckl2.org. 

Chapter 30 Assessment 

Provided to teachers upon request at teachers-requests@ckl2.org. 

Chapter 30 Assessment Answers 

Provided to teachers upon request at teachers-requests@ckl2.org. 



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